%0 Journal Article %A I. V. Gel'man %T Stability of abstract boundary value problems in a bounded region under weak perturbations of boundary operators %J Doklady Akademii Nauk %D 1968 %P 264-266 %V 179 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1968_179_2_a3/ %G ru %F DAN_1968_179_2_a3