@article{DE_1995_31_4_a3,
     author = {B. S. Kalitin},
     title = {On the method of sign-constant {Lyapunov} functions for nonautonomous differential systems},
     journal = {Differencialʹnye uravneni\^a},
     pages = {583--590},
     publisher = {mathdoc},
     volume = {31},
     number = {4},
     year = {1995},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1995_31_4_a3/}
}