%0 Journal Article
%A J. Sjöstrand
%A J.J. Duistermaat
%T A Global Construction for Pseudo-Differential Operators with Non-Involutive Characteristcs.
%J Inventiones mathematicae
%D 1973
%P 209-226
%V 20
%I mathdoc
%U http://geodesic.mathdoc.fr/item/IM_1973__20_142214/
%F IM_1973__20_142214