@article{DE_1984_20_8_a1,
     author = {E. E. Barbashina},
     title = {A package with variable control {variations.~I}},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1297--1308},
     year = {1984},
     volume = {20},
     number = {8},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1984_20_8_a1/}
}