TY  - JOUR
AU  - L. A. Cherkas
AU  - A. A. Grin'
TI  - A Dulac function in a half-plane in the form of a polynomial of the second degree for a quadratic system
JO  - Differencialʹnye uravneniâ
PY  - 1998
SP  - 1346
EP  - 1348
VL  - 34
IS  - 10
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1998_34_10_a7/
LA  - ru
ID  - DE_1998_34_10_a7
ER  -