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@article{DE_1968_4_9_a18, author = {V. V. Amel'kin}, title = {The periodic solutions of a certain system with a small parameter}, journal = {Differencialʹnye uravneni\^a}, pages = {1720--1723}, publisher = {mathdoc}, volume = {4}, number = {9}, year = {1968}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1968_4_9_a18/} }
V. V. Amel'kin. The periodic solutions of a certain system with a small parameter. Differencialʹnye uravneniâ, Tome 4 (1968) no. 9, pp. 1720-1723. http://geodesic.mathdoc.fr/item/DE_1968_4_9_a18/