%0 Journal Article
%A E. M. Karchevskii
%A S. I. Solov'ev
%T Investigation of a spectral problem for the Helmholtz operator on the plane
%J Differencialʹnye uravneniâ
%D 2000
%P 563-565
%V 36
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_2000_36_4_a20/
%G ru
%F DE_2000_36_4_a20