@article{DE_1968_4_5_a21,
     author = {I. N. Blinov},
     title = {A certain class of improper systems},
     journal = {Differencialʹnye uravneni\^a},
     pages = {949--951},
     publisher = {mathdoc},
     volume = {4},
     number = {5},
     year = {1968},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1968_4_5_a21/}
}