%0 Journal Article %A N. A. Izobov %T On a set of lower indices of a linear differential system %J Differencialʹnye uravneniâ %D 1965 %P 469-477 %V 1 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1965_1_4_a6/ %G ru %F DE_1965_1_4_a6