%0 Journal Article
%A G. M. Zhislin
%A A. G. Sigalov
%T On the mixed spectrum of certain higher-dimensional differential operators of quantum mechanics
%J Doklady Akademii Nauk
%D 1964
%P 1329-1331
%V 157
%N 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1964_157_6_a17/
%G ru
%F DAN_1964_157_6_a17