%0 Journal Article
%A M. M. Gekhtman
%T On the spectrum of a non-selfadjoint differential operator of even order
%J Doklady Akademii Nauk
%D 1963
%P 726-729
%V 150
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1963_150_4_a4/
%G ru
%F DAN_1963_150_4_a4