@article{DE_1981_17_12_a17,
     author = {G. S. Osipenko},
     title = {Submanifolds of codimension $1$ and the perturbation of homogeneous systems},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2274--2277},
     publisher = {mathdoc},
     volume = {17},
     number = {12},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1981_17_12_a17/}
}