%0 Journal Article %A Reinhard Pöschel %A Klaus Denecke %T A characterization of Sheffer functions by hyperidentities. %J Semigroup forum %D 1988 %P 351-362 %V 37 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/SF_1988__37_1_134937/ %F SF_1988__37_1_134937