%0 Journal Article
%A A. E. Evzhanov
%T A lower bound for the sum of squares of fundamental functions of a second-order selfadjoint elliptic operator
%J Differencialʹnye uravneniâ
%D 1987
%P 62-72
%V 23
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1987_23_1_a6/
%G ru
%F DE_1987_23_1_a6