TY  - JOUR
AU  - L. A. Cherkas
AU  - L. I. Zhilevich
TI  - Some tests for the absence or uniqueness of limit cycles
JO  - Differencialʹnye uravneniâ
PY  - 1970
SP  - 1170
EP  - 1178
VL  - 6
IS  - 7
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1970_6_7_a2/
LA  - ru
ID  - DE_1970_6_7_a2
ER  -