@article{1077476768, author = {Bell, P. O.}, title = {Projective differential invariants of a curve of a surface}, journal = {Duke Math. J.}, volume = {18}, number = {1}, year = {1951}, pages = { 697-705}, language = {en}, url = {http://dml.mathdoc.fr/item/1077476768} }
Bell, P. O. Projective differential invariants of a curve of a surface. Duke Math. J., Tome 18 (1951) no. 1, pp. 697-705. http://gdmltest.u-ga.fr/item/1077476768/