@article{DE_1967_3_4_a10,
     author = {M. G. Khudai-Verenov},
     title = {A remark on limit cycles of an equation},
     journal = {Differencialʹnye uravneni\^a},
     pages = {692--694},
     publisher = {mathdoc},
     volume = {3},
     number = {4},
     year = {1967},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1967_3_4_a10/}
}