%0 Journal Article
%A I. V. Skrypnik
%T On a topological characteristic of general nonlinear elliptic operators
%J Doklady Akademii Nauk
%D 1978
%P 538-541
%V 239
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1978_239_3_a9/
%G ru
%F DAN_1978_239_3_a9