TY  - JOUR
AU  - L. A. Cherkas
AU  - I. L. Shevtsov
TI  - Normal-Size Limit Cycles of Quadratic Systems with a Structurally Unstable Focus
JO  - Differencialʹnye uravneniâ
PY  - 2004
SP  - 1076
EP  - 1084
VL  - 40
IS  - 8
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_2004_40_8_a7/
LA  - ru
ID  - DE_2004_40_8_a7
ER  -