TY  - JOUR
AU  - Bularas Driss
AU  - N. I. Vulpe
AU  - K. S. Sibirskii
TI  - Solution of a problem of the center ``in the large'' for a general quadratic differential system
JO  - Differencialʹnye uravneniâ
PY  - 1989
SP  - 1856
EP  - 1862
VL  - 25
IS  - 11
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1989_25_11_a3/
LA  - ru
ID  - DE_1989_25_11_a3
ER  -