%0 Journal Article %A A. N. Vetokhin %T The exact descriptive type of the set of proper linear systems %J Differencialʹnye uravneniâ %D 2000 %P 1128-1129 %V 36 %N 8 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_2000_36_8_a15/ %G ru %F DE_2000_36_8_a15