%0 Journal Article
%A B. Yu. Sternin
%T Differential equations of subprincipal type
%J Sbornik. Mathematics
%D 1986
%P 37-67
%V 53
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/SM_1986_53_1_a2/
%G en
%F SM_1986_53_1_a2