%0 Journal Article %A B. F. Ivanov %T A frequency criterion for smoothness, with respect to the parameters, of solutions of a class of linear systems %J Differencialʹnye uravneniâ %D 1997 %P 1001 %V 33 %N 7 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1997_33_7_a20/ %G ru %F DE_1997_33_7_a20