%0 Journal Article
%A Karl-Peter Hadeler
%T On the spectrum of normal operators and perturbations of them
%J Doklady Akademii Nauk
%D 1964
%P 1042-1043
%V 158
%N 5
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1964_158_5_a9/
%G ru
%F DAN_1964_158_5_a9