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@article{DE_1970_6_7_a2, author = {L. A. Cherkas and L. I. Zhilevich}, title = {Some tests for the absence or uniqueness of limit cycles}, journal = {Differencialʹnye uravneni\^a}, pages = {1170--1178}, publisher = {mathdoc}, volume = {6}, number = {7}, year = {1970}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1970_6_7_a2/} }
L. A. Cherkas; L. I. Zhilevich. Some tests for the absence or uniqueness of limit cycles. Differencialʹnye uravneniâ, Tome 6 (1970) no. 7, pp. 1170-1178. http://geodesic.mathdoc.fr/item/DE_1970_6_7_a2/