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@article{DAN_1979_249_1_a9, author = {A. A. Martynyuk}, title = {A generalization of the second theorem of {N.\,N.~Bogolyubov's} averaging principle}, journal = {Doklady Akademii Nauk}, pages = {46--48}, publisher = {mathdoc}, volume = {249}, number = {1}, year = {1979}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1979_249_1_a9/} }
A. A. Martynyuk. A generalization of the second theorem of N.\,N.~Bogolyubov's averaging principle. Doklady Akademii Nauk, Tome 249 (1979) no. 1, pp. 46-48. http://geodesic.mathdoc.fr/item/DAN_1979_249_1_a9/