%0 Journal Article
%A Bergamasco, Adalberto P.
%A Zani, Sérgio Luís
%T Global Hypoellipticity of a Class of Second Order Operators
%J Canadian mathematical bulletin
%D 1994
%P 301-305
%V 37
%N 3
%U http://geodesic.mathdoc.fr/articles/10.4153/CMB-1994-045-4/
%R 10.4153/CMB-1994-045-4
%F 10_4153_CMB_1994_045_4