TY  - JOUR
AU  - S. I. Pokhozhaev
TI  - Periodic solutions of some nonlinear systems of ordinary differential equations
JO  - Differencialʹnye uravneniâ
PY  - 1980
SP  - 109
EP  - 116
VL  - 16
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1980_16_1_a12/
LA  - ru
ID  - DE_1980_16_1_a12
ER  -