TY  - JOUR
AU  - È. I. Grudo
TI  - The complex centers and foci of a second order differential equation
JO  - Differencialʹnye uravneniâ
PY  - 1978
SP  - 425
EP  - 434
VL  - 14
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1978_14_3_a3/
LA  - ru
ID  - DE_1978_14_3_a3
ER  -