TY - JOUR AU - A. A. Liverovskiy AU - N. N. Petrov TI - Some differential-topological problems in control theory JO - Differencialʹnye uravneniâ PY - 1991 SP - 771 EP - 777 VL - 27 IS - 5 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/DE_1991_27_5_a5/ LA - ru ID - DE_1991_27_5_a5 ER -