Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DAN_1973_210_3_a4, author = {V. V. Lychagin}, title = {Local classification of first-order nonlinear partial differential equations}, journal = {Doklady Akademii Nauk}, pages = {525--528}, publisher = {mathdoc}, volume = {210}, number = {3}, year = {1973}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1973_210_3_a4/} }
V. V. Lychagin. Local classification of first-order nonlinear partial differential equations. Doklady Akademii Nauk, Tome 210 (1973) no. 3, pp. 525-528. http://geodesic.mathdoc.fr/item/DAN_1973_210_3_a4/