1. R. DESCARTES: Lettre à Mersenne, October-November 1631. Quoted by A. Koyré, Etudes galiléennes, Hermann, vol. II, 1939, p. 50.
2. LAPLACE: Mécanique céleste, Première partie, livre I, an VII. Readers to whom Laplace's works are not available may consult Dugas' analysis (ref. [30] of Appendix I, vol. I, p. 338). See also Whittaker (ref. [29] of Appendix I, vol. II, p. 47).
3. Les Axiomes de la Mécanique;PAINLEVÉ,1922
4. Vitesse et univers relativiste;ABELÉ,1954
5. Zur Elektrodynamik bewegter Körper;EINSTEIN;Ann. Physik,1905