@article{DE_1977_13_9_a19,
     author = {V. I. Zubov},
     title = {Stability of integral manifolds},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1720--1722},
     publisher = {mathdoc},
     volume = {13},
     number = {9},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1977_13_9_a19/}
}