@article{DE_1984_20_8_a6,
     author = {A. F. Zubova},
     title = {Investigation of the stability of oscillatory systems},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1341--1348},
     publisher = {mathdoc},
     volume = {20},
     number = {8},
     year = {1984},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1984_20_8_a6/}
}