TY  - JOUR
AU  - V. V. Amel'kin
AU  - V. È. Zhavnerchik
TI  - Periodic solutions of certain second order equations
JO  - Differencialʹnye uravneniâ
PY  - 1976
SP  - 1147
EP  - 1150
VL  - 12
IS  - 7
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1976_12_7_a0/
LA  - ru
ID  - DE_1976_12_7_a0
ER  -