@article{DE_1990_26_3_a6,
     author = {B. S. Klebanov},
     title = {The method of sectors in the proof of {Lyapunov} instability},
     journal = {Differencialʹnye uravneni\^a},
     pages = {408--414},
     publisher = {mathdoc},
     volume = {26},
     number = {3},
     year = {1990},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1990_26_3_a6/}
}