TY  - JOUR
AU  - K. S. Sibirskii
TI  - Centroaffine invariant center conditions in the sense of Dulac for a quadratic differential system
JO  - Differencialʹnye uravneniâ
PY  - 1986
SP  - 954
EP  - 961
VL  - 22
IS  - 6
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1986_22_6_a4/
LA  - ru
ID  - DE_1986_22_6_a4
ER  -