@article{DE_1976_12_4_a23,
     author = {R. A. Prokhorova},
     title = {On the question of stability with respect to the first approximation},
     journal = {Differencialʹnye uravneni\^a},
     pages = {766--769},
     publisher = {mathdoc},
     volume = {12},
     number = {4},
     year = {1976},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1976_12_4_a23/}
}