%0 Journal Article
%A A. I. Vol'pert
%T The index of systems of two-dimensional singular integral equations
%J Doklady Akademii Nauk
%D 1962
%P 776-777
%V 142
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1962_142_4_a7/
%G ru
%F DAN_1962_142_4_a7