@article{DAN_1973_210_1_a0,
     author = {A. M. Vinogradov},
     title = {Multivalued solutions and a principle of classification of nonlinear differential equations},
     journal = {Doklady Akademii Nauk},
     pages = {11--14},
     publisher = {mathdoc},
     volume = {210},
     number = {1},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1973_210_1_a0/}
}