%0 Journal Article
%A B. R. Vainberg
%A V. V. Grushin
%T Uniformly nonelliptic problems. I
%J Sbornik. Mathematics
%D 1967
%P 543-568
%V 1
%N 4
%U http://geodesic.mathdoc.fr/item/SM_1967_1_4_a4/
%G en
%F SM_1967_1_4_a4