@article{RM_1975_30_1_a2,
     author = {V. V. Lychagin},
     title = {Lokal classification of non-lineral first order partial differential equations},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {105--175},
     publisher = {mathdoc},
     volume = {30},
     number = {1},
     year = {1975},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_1975_30_1_a2/}
}