TY  - JOUR
AU  - A. M. Samoilenko
TI  - Periodic solutions of second-order nonlinear equations
JO  - Differencialʹnye uravneniâ
PY  - 1967
SP  - 1903
EP  - 1912
VL  - 3
IS  - 11
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1967_3_11_a6/
LA  - ru
ID  - DE_1967_3_11_a6
ER  -