%0 Journal Article
%A O. A. Kovaleva
%T On a~property of the index of non-local elliptic problems
%J Trudy Matematicheskogo Instituta imeni V.A. Steklova
%D 1999
%P 843-844
%V 54
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/RM_1999_54_4_a13/
%G en
%F RM_1999_54_4_a13