%0 Journal Article
%A Yu. V. Egorov
%T On pseudo-differential operators of the principal type
%J Doklady Akademii Nauk
%D 1966
%P 778-780
%V 171
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1966_171_4_a3/
%G ru
%F DAN_1966_171_4_a3