@article{DE_1979_15_11_a4,
     author = {A. F. Zubova},
     title = {Investigation of oscillations and stability},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1960--1966},
     publisher = {mathdoc},
     volume = {15},
     number = {11},
     year = {1979},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1979_15_11_a4/}
}