%0 Journal Article %A O. A. Liskovets %T Stability of quasi-solutions for equations with a closed operator %J Differencialʹnye uravneniâ %D 1971 %P 1707-1709 %V 7 %N 9 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1971_7_9_a20/ %G ru %F DE_1971_7_9_a20