%0 Journal Article
%A V. A. Kondratiev
%A S. D. Èidel'man
%T On nonnegative solutions of overdetermined systems of partial differential equations
%J Doklady Akademii Nauk
%D 1977
%P 513-516
%V 237
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1977_237_3_a2/
%G ru
%F DAN_1977_237_3_a2