@article{DE_1984_20_3_a5,
     author = {Yu. V. Malyshev and V. P. Zakharov},
     title = {Annular domains that contain limit cycles},
     journal = {Differencialʹnye uravneni\^a},
     pages = {408--413},
     publisher = {mathdoc},
     volume = {20},
     number = {3},
     year = {1984},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1984_20_3_a5/}
}