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@article{DE_1971_7_8_a0, author = {Yu. N. Bibikov}, title = {The existence of conditionally periodic solutions of systems of differential equations}, journal = {Differencialʹnye uravneni\^a}, pages = {1347--1356}, publisher = {mathdoc}, volume = {7}, number = {8}, year = {1971}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1971_7_8_a0/} }
Yu. N. Bibikov. The existence of conditionally periodic solutions of systems of differential equations. Differencialʹnye uravneniâ, Tome 7 (1971) no. 8, pp. 1347-1356. http://geodesic.mathdoc.fr/item/DE_1971_7_8_a0/