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@article{DE_1991_27_3_a25, author = {D. S. Ushkho and I. V. Chaika}, title = {Limit cycles of an autonomous system with algebraic right-hand sides}, journal = {Differencialʹnye uravneni\^a}, pages = {544--546}, publisher = {mathdoc}, volume = {27}, number = {3}, year = {1991}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1991_27_3_a25/} }
D. S. Ushkho; I. V. Chaika. Limit cycles of an autonomous system with algebraic right-hand sides. Differencialʹnye uravneniâ, Tome 27 (1991) no. 3, pp. 544-546. http://geodesic.mathdoc.fr/item/DE_1991_27_3_a25/