Mac Lane, Saunders (1936), "Some interpretations of abstract linear dependence in terms of projective geometry", American Journal of Mathematics, The Johns Hopkins University Press, 58 (1): 236–240, doi:10.2307/2371070, JSTOR2371070.
Mac Lane, Saunders (1936), "Some interpretations of abstract linear dependence in terms of projective geometry", American Journal of Mathematics, The Johns Hopkins University Press, 58 (1): 236–240, doi:10.2307/2371070, JSTOR2371070.