@article{DE_1973_9_12_a2,
     author = {Yu. V. Malyshev},
     title = {Systems with an invariant set},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2141--2145},
     publisher = {mathdoc},
     volume = {9},
     number = {12},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1973_9_12_a2/}
}