TY  - JOUR
AU  - E. V. Voskresenskii
TI  - Periodic solutions of nonlinear systems and the comparison method
JO  - Differencialʹnye uravneniâ
PY  - 1992
SP  - 571
EP  - 576
VL  - 28
IS  - 4
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1992_28_4_a2/
LA  - ru
ID  - DE_1992_28_4_a2
ER  -