%0 Journal Article %A Celso Martinez %A %T A note on a formula for the fractional powers of infinitesimal generators of semigroups %J Studia Mathematica %D 1996 %P 247-254 %V 119 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/sm-119-3-247-254/ %R 10.4064/sm-119-3-247-254 %G en %F 10_4064_sm_119_3_247_254