%0 Journal Article %A Xuebo, Luo %T Necessary and Sufficient Conditions for Hypoellipticity for a Class of Convolution Operators %J Canadian journal of mathematics %D 1994 %P 212-224 %V 46 %N 1 %U http://geodesic.mathdoc.fr/articles/10.4153/CJM-1994-008-1/ %R 10.4153/CJM-1994-008-1 %F 10_4153_CJM_1994_008_1