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@article{DE_1995_31_6_a22, author = {V. G. Romanovsky}, title = {Center conditions for a cubic system with four complex parameters}, journal = {Differencialʹnye uravneni\^a}, pages = {1091--1093}, publisher = {mathdoc}, volume = {31}, number = {6}, year = {1995}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1995_31_6_a22/} }
V. G. Romanovsky. Center conditions for a cubic system with four complex parameters. Differencialʹnye uravneniâ, Tome 31 (1995) no. 6, pp. 1091-1093. http://geodesic.mathdoc.fr/item/DE_1995_31_6_a22/