TY  - JOUR
AU  - L. A. Cherkas
TI  - Conditions for the center for certain equations of the form $yy'=P(x)+Q(x)y+R(x)y^2$
JO  - Differencialʹnye uravneniâ
PY  - 1972
SP  - 1435
EP  - 1439
VL  - 8
IS  - 8
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1972_8_8_a12/
LA  - ru
ID  - DE_1972_8_8_a12
ER  -