@article{DE_1970_6_2_a1,
     author = {R. \`E. Vinograd and N. A. Izobov},
     title = {Solution of the {Ljapunov} stability problem by the first approximation},
     journal = {Differencialʹnye uravneni\^a},
     pages = {230--242},
     publisher = {mathdoc},
     volume = {6},
     number = {2},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1970_6_2_a1/}
}