@article{INTG_1981_12_a4,
     author = {N. V. Stepanov},
     title = {Geometry of differential equations},
     journal = {Itogi Nauki i Tekhniki. Seriya Problemy Geometrii. Trudy Geometricheskogo Seminara},
     pages = {127--164},
     publisher = {mathdoc},
     volume = {12},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/INTG_1981_12_a4/}
}