TY  - JOUR
AU  - A. Yu. Levin
TI  - On linear second-order differential equations
JO  - Doklady Akademii Nauk
PY  - 1963
SP  - 1257
EP  - 1260
VL  - 153
IS  - 6
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1963_153_6_a7/
LA  - ru
ID  - DAN_1963_153_6_a7
ER  -