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@article{IVM_1964_1_a3, author = {V. I. Voilokov}, title = {Periodic solutions of non-linear oscillatory systems with one degree of freedom}, journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika}, pages = {19--27}, publisher = {mathdoc}, number = {1}, year = {1964}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/IVM_1964_1_a3/} }
V. I. Voilokov. Periodic solutions of non-linear oscillatory systems with one degree of freedom. Izvestiâ vysših učebnyh zavedenij. Matematika, no. 1 (1964), pp. 19-27. http://geodesic.mathdoc.fr/item/IVM_1964_1_a3/