@article{DE_1990_26_11_a7,
     author = {V. \`E. Zhavnerchik},
     title = {A stability problem in one critical case},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1895--1898},
     year = {1990},
     volume = {26},
     number = {11},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1990_26_11_a7/}
}