%0 Journal Article %A Yu. M. Semenov %T The structure of the set of almost instantaneous zero-attainability %J Differencialʹnye uravneniâ %D 1990 %P 989-997 %V 26 %N 6 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1990_26_6_a7/ %G ru %F DE_1990_26_6_a7