TY  - JOUR
AU  - A. A. Liverovskiy
AU  - N. N. Petrov
TI  - Letter to the editors: ``Some differential-topological problems in control theory''
JO  - Differencialʹnye uravneniâ
PY  - 1991
SP  - 2201
VL  - 27
IS  - 12
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1991_27_12_a31/
LA  - ru
ID  - DE_1991_27_12_a31
ER  -