%0 Journal Article %A Rodino, Luigi %A De Donno, Giuseppe %T Gevrey hypoellipticity for partial differential equations with characteristics of higher multiplicity. %J Rendiconti del seminario matematico %D 2000 %P 435-448 %V 58 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/RSM_2000__58_4_125122/ %G en %F RSM_2000__58_4_125122