Building Blocks (toy)
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Building blocks (also construction blocks) are modular construction parts, usually made of
plastic Plastics are a wide range of synthetic polymers, synthetic or Semisynthesis, semisynthetic materials composed primarily of Polymer, polymers. Their defining characteristic, Plasticity (physics), plasticity, allows them to be Injection moulding ...
, which can be assembled in a form-fit manner. The basic components are usually cuboid-shaped, cylindrically studded at the top in a grid pattern, hollow-bodied at the bottom and smooth at the sides. The structured upper surface interacts by
friction Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. Types of friction include dry, fluid, lubricated, skin, and internal -- an incomplete list. The study of t ...
and positive locking with the correspondingly negative lower surface of other clamping components, so that complex designs can be assembled. The design allows the parts to be connected with compressive force and the blocks to be clamped with plastic pins.


Characteristics

According to the systematics of science of play, most clamping building block systems belong to the game classification of
educational toys Educational toys (sometimes also called "instructive toys") are objects of play, generally designed for children. Educational Toys help with motivation, helping kids use their imagination while still pulling in the real world. These toys are imp ...
or more specific
construction toys Construction are processes involved in delivering buildings, infrastructure, industrial facilities, and associated activities through to the end of their life. It typically starts with planning, financing, and design that continues until the a ...
. Characteristic features of building blocks are: *
modularity Modularity is the degree to which a system's components may be separated and recombined, often with the benefit of flexibility and variety in use. The concept of modularity is used primarily to reduce complexity by breaking a system into varying ...
: According to the construction set principle, the whole can be divided into parts and reassembled along defined locations. * Variability: as few as seven 4×2 bricks of the same color can be combined in over 85 billion ways. * Recombinability: bricks can be arranged differently to each other again and again. Desirable characteristics are: * Fit:
Tolerances Engineering tolerance is the permissible limit or limits of variation in: # a physical dimension; # a measured value or physical property of a material, manufactured object, system, or service; # other measured values (such as temperature, hu ...
of a few
micrometers The micrometre (Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a unit of length in the International System ...
prevent jamming, stepping, or detectable gaps between bricks. * Elasticity: By slightly deforming the stones during clamping, a permanent clamping or mechanical adhesive effect is achieved. The tiny difference in size between the nub and the stud receptacle must be compensated for elastically. However, some early building bricks were not designed to clamp together, rather relied upon gravity alone to hold structures together. * Shape, color and
thermostability In materials science and molecular biology, thermostability is the ability of a substance to resist irreversible change in its chemical or physical structure, often by resisting decomposition or polymerization, at a high relative temperature. T ...
: Despite the mechanical stress of the bricks, no
plastic deformation In engineering, deformation (the change in size or shape of an object) may be ''elastic'' or ''plastic''. If the deformation is negligible, the object is said to be ''rigid''. Main concepts Occurrence of deformation in engineering application ...
or
fracture Fracture is the appearance of a crack or complete separation of an object or material into two or more pieces under the action of stress (mechanics), stress. The fracture of a solid usually occurs due to the development of certain displacemen ...
should occur due to deformation or
shock Shock may refer to: Common uses Healthcare * Acute stress reaction, also known as psychological or mental shock ** Shell shock, soldiers' reaction to battle trauma * Circulatory shock, a medical emergency ** Cardiogenic shock, resulting from ...
, neither function nor appearance should be diminished. *
Chemical stability In chemistry, chemical stability is the thermodynamic stability of a chemical system, in particular a chemical compound or a polymer. Colloquially, it may instead refer to kinetic persistence, the shelf-life of a metastable substance or system; t ...
: high resistance to weathering, natural
ultraviolet Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of ...
and
ionizing radiation Ionizing (ionising) radiation, including Radioactive decay, nuclear radiation, consists of subatomic particles or electromagnetic waves that have enough energy per individual photon or particle to ionization, ionize atoms or molecules by detaching ...
. *
Wear resistance Wear is the damaging, gradual removal or deformation of material at solid surfaces. Causes of wear can be mechanical (e.g., erosion) or chemical (e.g., corrosion). The study of wear and related processes is referred to as tribology. Wear in ...
despite reversibility: clamp connections should be mechanically separable residue-free, with as little abrasion as possible. The studs of clamping components initially hold in the other component by static friction, so called
stiction Stiction (a portmanteau of the words '' static'' and ''friction'') is the force that needs to be overcome to enable relative motion of stationary objects in contact. Any solid objects pressing against each other (but not sliding) will require some ...
, which is supported by plasticity of the selected material - it prevents them from simply slipping out of the other component again. In terms of clamping components, the force required to pull a stud out of its holder is also known colloquially as the "clamping force". Blocks from different manufacturers sometimes differ in this respect. The main force acting transversely to the studs is the form fit.


Delimitation

Compared to most
ceramic A ceramic is any of the various hard, brittle, heat-resistant, and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. Common examples are earthenware, porcela ...
or wooden kits, constructions can be created that can also withstand (to a limited extent) tensile forces. Compared to metal building sets or :de:Metallbaukasten, however, building block sets have only weak cohesiveness, since they usually do not require special connectors; however, cohesiveness can be increased by form-fitting cross-connections. Metal construction sets are usually more room-forming and about linkage constructions.


Pedagogical Merit

The handling of building block toys requires and trains the visuomotor, the coordination of
visual The visual system is the physiological basis of visual perception (the ability to detect and process light). The system detects, transduces and interprets information concerning light within the visible range to construct an image and buil ...
and
haptic perception Haptic perception ( "palpable", ''haptikόs'' "suitable for touch") means literally the ability "to grasp something", and is also known as stereognosis. Perception in this case is achieved through the active exploration of surfaces and objects by a ...
and the movement apparatus (eye-hand coordination, force dosage buildup),
fine motor skills Fine may refer to: Characters * Fran Fine, the title character of ''The Nanny'' * Sylvia Fine (''The Nanny''), Fran's mother on ''The Nanny'' * Officer Fine, a character in ''Tales from the Crypt'', played by Vincent Spano Legal terms * Fine ...
,
color perception Color vision, a feature of visual perception, is an ability to perceive differences between light composed of different frequencies independently of light intensity. Color perception is a part of the larger visual system and is mediated by a co ...
,
spatial visualization ability Spatial visualization ability or visual-spatial ability is the ability to mentally manipulate 2-dimensional and 3-dimensional figures. It is typically measured with simple cognitive tests and is predictive of user performance with some kinds o ...
and
spatial cognition In cognitive psychology, spatial cognition is the acquisition, organization, utilization, and revision of knowledge about spatial environments. It is most about how animals, including humans, behave within space and the knowledge they built aroun ...
therein, and mental anticipation of action steps. It promotes
creativity Creativity is the ability to form novel and valuable Idea, ideas or works using one's imagination. Products of creativity may be intangible (e.g. an idea, scientific theory, Literature, literary work, musical composition, or joke), or a physica ...
,
imagination Imagination is the production of sensations, feelings and thoughts informing oneself. These experiences can be re-creations of past experiences, such as vivid memories with imagined changes, or completely invented and possibly fantastic scenes ...
as well as the play instinct and serves as a self-efficacy experience. Motor skills, spatial visualization ability and spatial cognition are particularly stimulated when the size of the blocks allows for the building of life-sized objects. Large blocks also favor collaboration and team work.


Material

Building blocks are almost always made from
thermoplastic A thermoplastic, or thermosoftening plastic, is any plastic polymer material that becomes pliable or moldable at a certain elevated temperature and solidifies upon cooling. Most thermoplastics have a high molecular weight. The polymer chains as ...
using the
injection molding Injection moulding (U.S. spelling: injection molding) is a manufacturing process for producing parts by injecting molten material into a mould, or mold. Injection moulding can be performed with a host of materials mainly including metals (for ...
process. (For other materials, see chapter
Sustainability Sustainability is a social goal for people to co-exist on Earth over a long period of time. Definitions of this term are disputed and have varied with literature, context, and time. Sustainability usually has three dimensions (or pillars): env ...
.) The material of the building blocks must be
elastic Elastic is a word often used to describe or identify certain types of elastomer, Elastic (notion), elastic used in garments or stretch fabric, stretchable fabrics. Elastic may also refer to: Alternative name * Rubber band, ring-shaped band of rub ...
to compensate for the difference in size between the studs and the recess and to create a permanent clamping effect, while remaining dimensionally stable and unbreakable even with multiple disassembly and reassembly and mechanical stress like tensile or compressing loads. Surfaces should be smooth but grippy and have
tolerances Engineering tolerance is the permissible limit or limits of variation in: # a physical dimension; # a measured value or physical property of a material, manufactured object, system, or service; # other measured values (such as temperature, hu ...
of only a few
micrometers The micrometre (Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a unit of length in the International System ...
, as the top and bottom of the clamping components serve as plug-in socket for each other.


Lego

Lego Lego (, ; ; stylised as LEGO) is a line of plastic construction toys manufactured by the Lego Group, a privately held company based in Billund, Denmark. Lego consists of variously coloured interlocking plastic bricks made of acrylonitri ...
initially used the material
cellulose acetate In biochemistry, cellulose acetate refers to any acetate ester of cellulose, usually cellulose diacetate. It was first prepared in 1865. A bioplastic, cellulose acetate is used as a film base in photography, as a component in some coatings, and ...
, an
acetate An acetate is a salt formed by the combination of acetic acid with a base (e.g. alkaline, earthy, metallic, nonmetallic, or radical base). "Acetate" also describes the conjugate base or ion (specifically, the negatively charged ion called ...
ester In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distin ...
of
cellulose Cellulose is an organic compound with the chemical formula, formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of glycosidic bond, β(1→4) linked glucose, D-glucose units. Cellulose is an important s ...
. Since 1963, Lego bricks have been made of the plastic acrylonitrile-butadiene-styrene
copolymer In polymer chemistry, a copolymer is a polymer derived from more than one species of monomer. The polymerization of monomers into copolymers is called copolymerization. Copolymers obtained from the copolymerization of two monomer species are som ...
(ABS). Transparent building elements are made of
polycarbonate Polycarbonates (PC) are a group of thermoplastic polymers containing carbonate ester, carbonate groups in their chemical structures. Polycarbonates used in engineering are strong, toughness, tough materials, and some grades are optically transp ...
("Makrolon") and
axle An axle or axletree is a central shaft for a rotation, rotating wheel and axle, wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In ...
s because of its higher rotational stiffness made of
polyamide A polyamide is a polymer with repeating units linked by amide bonds. Polyamides occur both naturally and artificially. Examples of naturally occurring polyamides are proteins, such as wool and silk. Artificially made polyamides can be made throug ...
(PA). ABS has a low specific gravity with a
density Density (volumetric mass density or specific mass) is the ratio of a substance's mass to its volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' (or ''d'') can also be u ...
of 1.03 to 1.07 g-cm−3. Thanks to its good resistance to impact, it is breaking strength, and a surface hardness of 50-60 hardness test by
Shore A coast (coastline, shoreline, seashore) is the land next to the sea or the line that forms the boundary between the land and the ocean or a lake. Coasts are influenced by the topography of the surrounding landscape and by aquatic erosion, su ...
makes it scratch-resistant to fingernails. The material is resistant to aqueous chemicals, but is unresistant to
solvents A solvent (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for p ...
such as
acetone Acetone (2-propanone or dimethyl ketone) is an organic compound with the chemical formula, formula . It is the simplest and smallest ketone (). It is a colorless, highly Volatile organic compound, volatile, and flammable liquid with a charact ...
. The plastic component tolerates heating up to a temperature of 80 °C and has good mechanical and acoustic
damping In physical systems, damping is the loss of energy of an oscillating system by dissipation. Damping is an influence within or upon an oscillatory system that has the effect of reducing or preventing its oscillation. Examples of damping include ...
properties. The
amorphous In condensed matter physics and materials science, an amorphous solid (or non-crystalline solid) is a solid that lacks the long-range order that is a characteristic of a crystal. The terms "glass" and "glassy solid" are sometimes used synonymousl ...
thermoplastics A thermoplastic, or thermosoftening plastic, is any plastic polymer material that becomes pliable or moldable at a certain elevated temperature and solidifies upon cooling. Most thermoplastics have a high molecular weight. The polymer chains as ...
are matt glossy, different colors are producible.


Sustainability

The
polymer degradation Polymer degradation is the reduction in the physical properties of a polymer, such as strength, caused by changes in its chemical composition. Polymers and particularly plastics are subject to degradation at all stages of their product life cycl ...
of building blocks made from acrylonitrile-butadiene-styrene copolymer (ABS) can take between 100 and 1300 years in the ocean, depending on conditions, according to a
University of Plymouth The University of Plymouth is a public research university based predominantly in Plymouth, England, where the main campus is located, but the university has campuses and affiliated colleges across South West England. With students, it is the ...
research finding, which is why some manufacturers are looking to switch to sustainable raw materials; some manufacturers make Lego-compatible bricks from wood, for example, from bioethanol or use resins from natural materials as a base, likewise, packaging is sometimes intended to become more environmentally friendly. There are also building blocks made of cardboard.


History

In 1934, the ''Rubber Specialties Company'' in the United States started production of its ''Bild-O-Brik'' rubber system. From 1935 to 1976, the ''Premo Rubber Company'' manufactured the
Minibrix Minibrix were construction kits manufactured from 1935 to 1976 in the UK. Developed in 1935, they enabled children to build their own miniature houses. Like the later and more famous construction toy, Lego, Minibrix consisted primarily of interloc ...
. The system consisted of brown rubber blocks with a basic grid size of . Beginning in 1939, ''Halsam Products'' manufactured its ''American Bricks'' from pressed wood. "ELGO Plastics, Inc. was established as a division of Halsam Products Company in 1941." It produced building blocks under the name ''American Plastic Bricks'' from 1946, and was the dominant American supplier through the 1950's. A full history of Halsam and its founders cites the existence of interlocking plastic bricks prior to LEGO in America. In 1949, the Danish company ''Lego'' began industrial production of its ''Automatic Binding Brick'', which, however, like its predecessors, was hollow inside and therefore produced very little adhesion. The bricks are an almost identical copy of the 1947 ''Self-locking Building Bricks'' of the English brand ''Kiddicraft'' by toy developer
Hilary Page Hilary "Harry" Fisher Page (20 August 1904 – 24 June 1957) was an English toy maker and inventor of Self-Locking Building Bricks, the predecessor of Lego bricks. He founded the Kiddicraft toy company. Early life Hilary "Harry" Fisher Page ...
. In the 1997 publication ''Developing a Product'', ''Lego'' explicitly refers to the origin of the building blocks:


Possible combinations

Building blocks can be combined with each other in many ways. Two same-colored 4×2 bricks can be arranged in 24 ways, with three this is already 1560. The number of
combination In mathematics, a combination is a selection of items from a set that has distinct members, such that the order of selection does not matter (unlike permutations). For example, given three fruits, say an apple, an orange and a pear, there are ...
s increases to over 85 billion with only seven same-colored 4×2 bricks, as a paper from the Mathematics Department of
Aarhus University Aarhus University (, abbreviated AU) is a public research university. Its main campus is located in Aarhus, Denmark. It is the second largest and second oldest university in Denmark. The university is part of the Coimbra Group, the Guild, and Ut ...
states.


Models and manufacturers

The building blocks are usually sold in building block sets with building instructions, less often as single-variety or mixed bulk. In addition to the main model of a set, building instructions for an alternative model ("B-model") are occasionally included, often advertised as such ("2-in-1", "3-in-1"). Building blocks are produced in different shapes, sizes and systems worldwide by various manufacturers, with the majority of manufacturers following Lego's construction dimensions, a grid size of 8 × 8 mm (and other shape specifications), to keep their plug-in systems compatible. In addition to the standard shapes, most manufacturers produce special bricks onto which, in turn, bricks of the type described at the beginning can be placed or clamped. Ready-to-assemble giant cardboard blocks have also recently appeared on the market: due to their size they are sold as flat cardboard sheets that are then assembled into big building blocks. Some manufacturers concentrate on so-called MOCs ("My Own Creation"), which have been developed by brick fans and released or licensed for reproduction.


Litigation for trademark protection


Lego system

The
Lego Lego (, ; ; stylised as LEGO) is a line of plastic construction toys manufactured by the Lego Group, a privately held company based in Billund, Denmark. Lego consists of variously coloured interlocking plastic bricks made of acrylonitri ...
company repeatedly sued competing building block manufacturers in court. The lawsuits were mostly unsuccessful, as the courts evaluated the functional design of the base brick as an issue of
patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an sufficiency of disclosure, enabling discl ...
rather than
trademark A trademark (also written trade mark or trade-mark) is a form of intellectual property that consists of a word, phrase, symbol, design, or a combination that identifies a Good (economics and accounting), product or Service (economics), service f ...
law, and all relevant Lego patents have expired. Lego itself largely adopted the dimensions of the bricks in the late 1940s from an invention by British toy developer
Hilary Page Hilary "Harry" Fisher Page (20 August 1904 – 24 June 1957) was an English toy maker and inventor of Self-Locking Building Bricks, the predecessor of Lego bricks. He founded the Kiddicraft toy company. Early life Hilary "Harry" Fisher Page ...
. Lego and
Tyco Toys Tyco Toys was an American toy manufacturer. It was acquired by Mattel in 1997, becoming one of its brands. History Formation of Tyco The company was established as Mantua Metal Products by John Tyler and Jim Thomas in 1926, producing model bo ...
fought in U.S. courts over Tyco's interlocking bricks in the 1980s, with both manufacturers claiming victory. On August 31, 1987, a U.S. District Court ruled that Tyco could continue to manufacture Lego system-compatible bricks with the product name ''Super Blocks,'' but ordered Tyco to cease and desist from using the Lego trademark and from advertising with "Lego, but only cheaper". Lego's Hong Kong lawsuit against ''Tyco Super Blocks'' obtained an injunction forcing Tyco to stop making Lego-compatible bricks from after 1973. Tyco was also sued by Lego in Austria, Italy and Canada. The Canadian manufacturer ''Mega Bloks'' was sued, Lego asserting that their use of the composite brick system of "studs and tubes" was an infringement of the trademarks held by Lego. On November 17, 2005, the
Supreme Court of Canada The Supreme Court of Canada (SCC; , ) is the highest court in the judicial system of Canada. It comprises nine justices, whose decisions are the ultimate application of Canadian law, and grants permission to between 40 and 75 litigants eac ...
upheld the right of ''Mega Bloks'' to continue selling the product in Canada. On November 12, 2008, the
General Court (European Union) The General Court, informally known as the European General Court (EGC), is a constituent court of the Court of Justice of the European Union. It hears actions taken against the institutions of the European Union by individuals and member stat ...
made a similar decision. On September 14, 2010, the
European Court of Justice The European Court of Justice (ECJ), officially the Court of Justice (), is the supreme court of the European Union in matters of European Union law. As a part of the Court of Justice of the European Union, it is tasked with interpreting ...
ruled that the eight-stud design of the original Lego brick "only fulfills a technical function ndcannot be registered as a trademark" (regarding brick replica; however, it is still protected as a 3D trademark regarding advertising purposes/company logos and suchlike). The English company ''Best-Lock Construction Toys'' sued ''Lego'' in German courts in 2004 and 2009. In the latter case, the German Federal Supreme Court rejected Lego trademark protection for the shape of its bricks. In 2002, Lego's Swiss subsidiary ''Interlego AG'' successfully sued the company ''Tianjin CoCo Toy Co. Ltd.'' for
copyright infringement Copyright infringement (at times referred to as piracy) is the use of Copyright#Scope, works protected by copyright without permission for a usage where such permission is required, thereby infringing certain exclusive rights granted to the c ...
. An appeals court found that many CoCo sets violated existing law. CoCo was ordered to stop manufacturing the infringing sets, publish a formal apology in the ''Beijing Daily,'' and pay a small compensation to ''Interlego.'' On appeal, the Supreme People's Court in Beijing upheld the court's ruling. In 2000, Lego applied for a three-dimensional trademark for its minifigures, which ''Best Lock'' had already duplicated in 1998. Thus, ''Best Lock'' sued in 2012 to revoke the trademark. On June 16, 2015, the European Court of Justice upheld Lego's figure trademark. Lego had filed its copyright claims in a U.S. customs database in 2009, which led to the confiscation of Best Lock shipments from Asia. In October 2011, Lego filed a lawsuit in
United States District Court The United States district courts are the trial courts of the United States federal judiciary, U.S. federal judiciary. There is one district court for each United States federal judicial district, federal judicial district. Each district cov ...
in Hartford against ''Best-Lock'' over the minifigure trademark. Mega Bloks won a case in the EU Court of Justice in 2010 against Lego's trademark registration of a red toy brick. Jon Capriola came up with the idea of a light-up brick called ''Laser Pegs'' in 2002, which was patented in 2006 and finally granted in 2009. Lawrence Rosen of ''LaRose Industries'' was approached by Capriola to invest in the company at the North American International Toy Fair in February 2011. Instead, Rosen applied for and received an accelerated patent in 2012, and LaRose Industries' Cra-Z-Art division then began producing ''Lite Brix'' light-up blocks. In 2013, Capriola's company sued Rosen for patent infringement, while Rosen filed for cancellation of his patent with the
United States Patent and Trademark Office The United States Patent and Trademark Office (USPTO) is an List of federal agencies in the United States, agency in the United States Department of Commerce, U.S. Department of Commerce that serves as the national patent office and trademark ...
. In 2014, ''Light Stax'' was introduced as another LED light-compatible brick. In 2011, Lego sued ''Guangdong Jumbo Grand Plastic Moulding Industrial'' for counterfeit packaging of ''BanBao''. The two companies settled out of court, with Guangdong agreeing to issue standalone packaging and produce a new figure called ToBees. In 2016, Lego announced that it would take legal action against Chinese manufacturer ''Guangdong Loongon'', which produces the ''Lepin'' brand and is known for
plagiarism Plagiarism is the representation of another person's language, thoughts, ideas, or expressions as one's own original work.From the 1995 ''Random House Dictionary of the English Language, Random House Compact Unabridged Dictionary'': use or close ...
s of Lego sets. In 2019, counterfeit Lego sets worth 26 million euros were seized in raids by Chinese police. In 2021, Lego has obtained a
cease-and-desist A cease and desist letter is a document sent by one party, often a business, to warn another party that they believe the other party is committing an unlawful act, such as copyright infringement, and that they will take legal action if the other ...
declaration in the German-speaking countries, according to which only original Lego bricks may also be called Lego. The cease-and-desist declaration argues that Lego is a
wordmark A wordmark or word mark is a text-only statement of the name of a product, service, company, organization, or institution which is used for purposes of identification and branding. A wordmark can be an actual word (e.g., Apple), a made-up term ...
. For many, however, Lego is a so-called deonym (word from a proper name or generalized brand name), i.e. (also) a generic name, which is to be prevented. The root cause can be found in the trademark act. Thus, for example, complex words have arisen in the German language that attempt to dignify the cease-and-desist declaration, which, however, is also understandable considering the history of the building block. Thus, it must be internalized that Lego is only a manufacturer of building blocks.


See also

*
Toy block Toy blocks (also building bricks, building blocks, or simply blocks) are wooden, plastic, or foam pieces of various shapes (cube, cylinder, arch etc.) and colors that are used as construction toys. Sometimes, toy blocks depict letters of the al ...


Literature

* * * (PDF; 3,3 MB) *


External video links

* (video in English; 8:02 min) * (video in German; 21:05 min). * (video in German; 33:58 min). * (video in German; 8:14 min).


External links

* Wolfgang Lenders
''Konkurrenz auf dem Noppenmarkt (Competition on the stud market)''.
in journal
''Brand eins''
vol. 3/2008. . * Michael Schäfer
''60 Jahre Lego-Brick: Ein Baustein trotzt der Digitalisierung (60 Years of Lego Brick: A Building Block Defies Digitization)''.
in journal: ''ComputerBase''. 2018-01-28


References

Construction toys Plastic toys Copyright infringement