%0 Journal Article
%A A. A. Ilyin
%T Lower bounds for sums of eigenvalues of elliptic operators and systems
%J Sbornik. Mathematics
%D 2013
%P 563-587
%V 204
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/SM_2013_204_4_a4/
%G en
%F SM_2013_204_4_a4