%0 Journal Article
%A V. I. Filippenko
%T Some criteria for discreteness of the negative part of the spectrum of a linear differential operator
%J Differencialʹnye uravneniâ
%D 1985
%P 728-731
%V 21
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1985_21_4_a23/
%G ru
%F DE_1985_21_4_a23