@article{DAN_1983_271_6_a8,
     author = {V. V. Lychagin},
     title = {Characteristic classes of solutions of differential equations},
     journal = {Doklady Akademii Nauk},
     pages = {1320--1324},
     publisher = {mathdoc},
     volume = {271},
     number = {6},
     year = {1983},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1983_271_6_a8/}
}