%0 Journal Article
%A V. A. Il'in
%T A lower bound of the sum of the squares of the fundamental functions, and of the number of the fundamental values, for an arbitrary $FSF$ of Laplace's operator
%J Differencialʹnye uravneniâ
%D 1970
%P 7-16
%V 6
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1970_6_1_a1/
%G ru
%F DE_1970_6_1_a1