TY  - JOUR
AU  - E. A. Andronova
TI  - On~the topology of quadratic systems with four (or more) limit cycles
JO  - Trudy Matematicheskogo Instituta imeni V.A. Steklova
PY  - 1986
SP  - 191
EP  - 192
VL  - 41
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/RM_1986_41_2_a7/
LA  - en
ID  - RM_1986_41_2_a7
ER  -