%0 Journal Article
%A I. A. Kipriyanov
%T Degenerate differential operators of principal type
%J Doklady Akademii Nauk
%D 1973
%P 1247-1250
%V 213
%N 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1973_213_6_a4/
%G ru
%F DAN_1973_213_6_a4