@article{1183495043, author = {Craig, H. V.}, title = {On a covariant differentiation process}, journal = {Bull. Amer. Math. Soc.}, volume = {37}, number = {12}, year = {1931}, pages = { 731-734}, language = {en}, url = {http://dml.mathdoc.fr/item/1183495043} }
Craig, H. V. On a covariant differentiation process. Bull. Amer. Math. Soc., Tome 37 (1931) no. 12, pp. 731-734. http://gdmltest.u-ga.fr/item/1183495043/