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@article{DE_1999_35_3_a0, author = {E. P. Volokitin and S. A. Treskov}, title = {On periodic solutions of a system of differential equations}, journal = {Differencialʹnye uravneni\^a}, pages = {291--295}, publisher = {mathdoc}, volume = {35}, number = {3}, year = {1999}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1999_35_3_a0/} }
E. P. Volokitin; S. A. Treskov. On periodic solutions of a system of differential equations. Differencialʹnye uravneniâ, Tome 35 (1999) no. 3, pp. 291-295. http://geodesic.mathdoc.fr/item/DE_1999_35_3_a0/