%0 Journal Article
%A Jöran Friberg
%T Partially Hypoelliptic Differential Equations of Finite Type.
%J Mathematica Scandinavica
%D 1961
%P 22-42
%V 9
%I mathdoc
%U http://geodesic.mathdoc.fr/item/MS2_1961__9_165760/
%F MS2_1961__9_165760