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@article{DAN_1963_148_3_a7, author = {A. Yu. Levin}, title = {Some questions on the oscillation of solutions of linear differential equations}, journal = {Doklady Akademii Nauk}, pages = {512--515}, publisher = {mathdoc}, volume = {148}, number = {3}, year = {1963}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1963_148_3_a7/} }
A. Yu. Levin. Some questions on the oscillation of solutions of linear differential equations. Doklady Akademii Nauk, Tome 148 (1963) no. 3, pp. 512-515. http://geodesic.mathdoc.fr/item/DAN_1963_148_3_a7/