%0 Journal Article
%A V. A. Ginzburg
%T A theorem on the index of differential systems and the geometry of
%J Doklady Akademii Nauk
%D 1985
%P 521-525
%V 281
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1985_281_3_a0/
%G ru
%F DAN_1985_281_3_a0