TY  - JOUR
AU  - L. A. Cherkas
TI  - A Precise Estimate of the Number of Limit Cycles of Autonomous Systems on the Plane
JO  - Differencialʹnye uravneniâ
PY  - 2003
SP  - 759
EP  - 768
VL  - 39
IS  - 6
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_2003_39_6_a4/
LA  - ru
ID  - DE_2003_39_6_a4
ER  -