TY  - JOUR
AU  - Yu. S. Kolesov
TI  - Positive periodic solutions of a class of differential equations of second order
JO  - Doklady Akademii Nauk
PY  - 1967
SP  - 264
EP  - 266
VL  - 172
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1967_172_2_a3/
LA  - ru
ID  - DAN_1967_172_2_a3
ER  -