%0 Journal Article %A V. N. Bobochko %T A singularly perturbed problem with a noninvertible limit operator %J Differencialʹnye uravneniâ %D 1990 %P 1453-1454 %V 26 %N 8 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1990_26_8_a22/ %G ru %F DE_1990_26_8_a22