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@article{IVM_1967_6_a7, author = {J. P. Konovalov and S. N. Shimanov}, title = {Periodic solutions of quasi-harmonic systems with retardation}, journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika}, pages = {59--67}, publisher = {mathdoc}, number = {6}, year = {1967}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/IVM_1967_6_a7/} }
J. P. Konovalov; S. N. Shimanov. Periodic solutions of quasi-harmonic systems with retardation. Izvestiâ vysših učebnyh zavedenij. Matematika, no. 6 (1967), pp. 59-67. http://geodesic.mathdoc.fr/item/IVM_1967_6_a7/