TY  - JOUR
AU  - I. A. Konovalov
TI  - Certain sufficient tests for the existence of limit cycles of a certain dynamic system
JO  - Differencialʹnye uravneniâ
PY  - 1971
SP  - 226
EP  - 231
VL  - 7
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1971_7_2_a4/
LA  - ru
ID  - DE_1971_7_2_a4
ER  -