This article contains a representative list of notable databases and search engines useful in an academic setting for finding and accessing articles in

academic journal An academic journal or scholarly journal is a periodical publication in which scholarship relating to a particular academic discipline is published. Academic journals serve as permanent and transparent forums for the presentation, scrutiny, and ...

institutional repositories An institutional repository is an archive for collecting, preserving, and disseminating digital copies of the intellectual output of an institution, particularly a research institution. Academics also utilize their IRs for archiving published work ...

, archives, or other collections of

scientific Science is a systematic endeavor that builds and organizes knowledge in the form of testable explanations and predictions about the universe. Science may be as old as the human species, and some of the earliest archeological evidence for ...

and

other Other often refers to: * Other (philosophy), a concept in psychology and philosophy Other or The Other may also refer to: Film and television * ''The Other'' (1913 film), a German silent film directed by Max Mack * ''The Other'' (1930 film), a ...

articles. Databases and search engines differ substantially in terms of coverage and retrieval qualities. Users need to account for qualities and limitations of databases and search engines, especially those searching systematically for records such as in systematic reviews or meta-analyses. As the distinction between a

database In computing, a database is an organized collection of data stored and accessed electronically. Small databases can be stored on a file system, while large databases are hosted on computer clusters or cloud storage. The design of databases s ...

and a search engine is unclear for these complex

document retrieval system Document retrieval is defined as the matching of some stated user query against a set of free-text records. These records could be any type of mainly natural language, unstructured text, such as newspaper articles, real estate records or paragraphs ...

s, see: * the general

list of search engines Search engines, including web search engines, selection-based search engines, metasearch engines, desktop search tools, and web portals and vertical market websites have a search facility for online databases. By content/topic General ...

for all-purpose search engines that can be used for academic purposes * the article about

bibliographic database A bibliographic database is a database of bibliographic records, an organized digital collection of references to published literature, including journal and newspaper articles, conference proceedings, reports, government and legal publications, ...

s for information about databases giving bibliographic information about finding books and journal articles. The terms "free", "subscription", and "free & subscription" will refer to the availability of the website as well as the journal articles used. Furthermore, some programs are only partly free (for example, accessing abstracts or a small number of items), whereas complete access is prohibited (login or institutional subscription required). The "Size" column denotes the number of documents (articles, publications, datasets, preprints) rather than the number of citations or references. The database itself should be the primary source of statistics, and if it is not accessible, the independent estimates released as journal papers should be. Notably, Google Scholar does not offer such detail, but the database's size has been calculated.

Operating services

Full-text aggregators

The main academic

full-text database A full-text database or a complete-text database is a database that contains the complete text of books, dissertations, journals, magazines, newspapers or other kinds of textual documents. They differ from bibliographic databases (which con ...

s are

open archives An open repository or open-access repository is a digital platform that holds research output and provides free, immediate and permanent access to research results for anyone to use, download and distribute. To facilitate open access such repositori ...

or link-resolution services, although others operate under different models such as mirroring or hybrid publishers. Such services typically provide access to full text and

full-text search In text retrieval, full-text search refers to techniques for searching a single computer-stored document or a collection in a full-text database. Full-text search is distinguished from searches based on metadata or on parts of the original texts ...

, but also metadata about items for which no full text is available. This list focuses on general-purpose services;

OpenDOAR OpenDOAR: Directory of Open Access Repositories is a UK-based website that lists open access repositories (including academic ones). It is searchable by locale, content, and other measures. The service does not require complete repository detail ...

can be used to find thousands open-access repositories. The table is sorted by the number of works for which full-text is made available.

Metadata services

Publishers

Content by most academic publishers is indexed by CrossRef,

DOAJ The Directory of Open Access Journals (DOAJ) is a website that hosts a community-curated list of open access journals, maintained by Infrastructure Services for Open Access (IS4OA). It was launched in 2003 with 300 open access journals. The proje ...

and/or DataCite. Some publishers are also listed separately in the table below.

Services no longer operating

The following services are no longer operating; this may be because they were not updated, abandoned entirely, replaced by other, etc.

References

{{DEFAULTSORT:Academic Databases and Search Engines