%0 Journal Article
%A V. I. Shevchenko
%T On the homotopy classification of Douglis–Nirenberg elliptic systems
%J Doklady Akademii Nauk
%D 1975
%P 1275-1277
%V 225
%N 6
%U http://geodesic.mathdoc.fr/item/DAN_1975_225_6_a9/
%G ru
%F DAN_1975_225_6_a9