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@article{DAN_1963_153_6_a7, author = {A. Yu. Levin}, title = {On linear second-order differential equations}, journal = {Doklady Akademii Nauk}, pages = {1257--1260}, publisher = {mathdoc}, volume = {153}, number = {6}, year = {1963}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1963_153_6_a7/} }
A. Yu. Levin. On linear second-order differential equations. Doklady Akademii Nauk, Tome 153 (1963) no. 6, pp. 1257-1260. http://geodesic.mathdoc.fr/item/DAN_1963_153_6_a7/