@article{DE_1983_19_5_a20,
     author = {T. V. Usacheva},
     title = {Stability of characteristics of diagonal systems of differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {909--911},
     publisher = {mathdoc},
     volume = {19},
     number = {5},
     year = {1983},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1983_19_5_a20/}
}