TY  - JOUR
AU  - N. N. Vinogradov
TI  - The existence of a periodic solution of a nonlinear system of three differential equations
JO  - Differencialʹnye uravneniâ
PY  - 1970
SP  - 1901
VL  - 6
IS  - 10
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1970_6_10_a20/
LA  - ru
ID  - DE_1970_6_10_a20
ER  -