@article{DE_1967_3_3_a0,
     author = {V. V. Nemytskii},
     title = {Topological classification of singular points and generalized {Ljapunov} functions},
     journal = {Differencialʹnye uravneni\^a},
     pages = {359--370},
     publisher = {mathdoc},
     volume = {3},
     number = {3},
     year = {1967},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1967_3_3_a0/}
}