%0 Journal Article
%A M. A. Gol'dman
%A S. N. Krachkovskii
%T On certain perturbations of a closed linear operator
%J Doklady Akademii Nauk
%D 1964
%P 507-509
%V 158
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1964_158_3_a1/
%G ru
%F DAN_1964_158_3_a1