TY  - JOUR
AU  - Josef Hainzl
TI  - On the number of limit cycles in perturbations of a two dimensional nonlinear differential system.
JO  - Aequationes mathematicae
PY  - 1997
SP  - 254
EP  - 274
VL  - 53
IS  - 1-2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/AM2_1997__53_1-2_137687/
ID  - AM2_1997__53_1-2_137687
ER  -