@article{1077472103, author = {Wang, Hsien-Chung}, title = {A projective invariant of a non-holonomic surface}, journal = {Duke Math. J.}, volume = {10}, number = {1}, year = {1943}, pages = { 565-574}, language = {en}, url = {http://dml.mathdoc.fr/item/1077472103} }
Wang, Hsien-Chung. A projective invariant of a non-holonomic surface. Duke Math. J., Tome 10 (1943) no. 1, pp. 565-574. http://gdmltest.u-ga.fr/item/1077472103/