TY  - JOUR
AU  - A. A. Andronov
AU  - E. A. Leontovich
TI  - Sufficient conditions for the ``structural instability of the first degree'' of a dynamical system on the plane
JO  - Differencialʹnye uravneniâ
PY  - 1970
SP  - 2121
EP  - 2134
VL  - 6
IS  - 12
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1970_6_12_a1/
LA  - ru
ID  - DE_1970_6_12_a1
ER  -