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@article{DE_1969_5_7_a20, author = {M. V. Dolov}, title = {The limit cycles of a certain class of differential equations}, journal = {Differencialʹnye uravneni\^a}, pages = {1330--1334}, publisher = {mathdoc}, volume = {5}, number = {7}, year = {1969}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1969_5_7_a20/} }
M. V. Dolov. The limit cycles of a certain class of differential equations. Differencialʹnye uravneniâ, Tome 5 (1969) no. 7, pp. 1330-1334. http://geodesic.mathdoc.fr/item/DE_1969_5_7_a20/