^Wilson, Edwin Bidwell (1901). Vector analysis: a text-book for the use of students of mathematics and physics, founded upon the lectures of J. Willard Gibbs. p. 125. hdl:2027/mdp.39015000962285. This is the likely origin of the speed/velocity terminology in vector physics.
^ abcElert, Glenn. "Speed & Velocity". The Physics Hypertextbook. Retrieved 8 June 2017.
^Wilson, Edwin Bidwell (1901). Vector analysis: a text-book for the use of students of mathematics and physics, founded upon the lectures of J. Willard Gibbs. p. 125. hdl:2027/mdp.39015000962285. This is the likely origin of the speed/velocity terminology in vector physics.
^Darling, David. "Fastest Spacecraft". Retrieved August 19, 2013.Jean Piaget, the intuition for the notion of speed in humans precedes that of duration, and is based on the notion of outdistancing.[11] Piaget studied this subject inspired by a question asked to him in 1928 by Albert Einstein: "In what order do children acquire the concepts of time and speed?"[12] Children's early concept of speed is based on "overtaking", taking only temporal and spatial orders into consideration, specifically: "A moving object is judged to be more rapid than another when at a given moment the first object is behind and a moment or so later ahead of the other object."[13]