%0 Journal Article
%A A. A. Liverovskiy
%A N. N. Petrov
%T Letter to the editors: ``Some differential-topological problems in control theory''
%J Differencialʹnye uravneniâ
%D 1991
%P 2201
%V 27
%N 12
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1991_27_12_a31/
%G ru
%F DE_1991_27_12_a31