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@article{DE_2000_36_1_a13, author = {A. P. Sadovskii}, title = {Center conditions and limit cycles in a cubic system of differential equations}, journal = {Differencialʹnye uravneni\^a}, pages = {98--102}, publisher = {mathdoc}, volume = {36}, number = {1}, year = {2000}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_2000_36_1_a13/} }
A. P. Sadovskii. Center conditions and limit cycles in a cubic system of differential equations. Differencialʹnye uravneniâ, Tome 36 (2000) no. 1, pp. 98-102. http://geodesic.mathdoc.fr/item/DE_2000_36_1_a13/