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@article{DAN_1958_121_2_a4, author = {A. Langenbach}, title = {On the application of the variation principle to some nonlinear differential equations}, journal = {Doklady Akademii Nauk}, pages = {214--217}, publisher = {mathdoc}, volume = {121}, number = {2}, year = {1958}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1958_121_2_a4/} }
A. Langenbach. On the application of the variation principle to some nonlinear differential equations. Doklady Akademii Nauk, Tome 121 (1958) no. 2, pp. 214-217. http://geodesic.mathdoc.fr/item/DAN_1958_121_2_a4/