%0 Journal Article
%A Yu. V. Egorov
%T Equations of principal type. Sufficient conditions for local solvability
%J Sbornik. Mathematics
%D 1983
%P 517-525
%V 44
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/SM_1983_44_4_a9/
%G en
%F SM_1983_44_4_a9