%0 Journal Article %A Alessio Fiscella %A Raffaella Servadei %A Enrico Valdinoci %T Density properties for fractional Sobolev spaces %J Annales Fennici Mathematici %D 2015 %P 235-253 %V 40 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.5186/aasfm.2015.40xx/ %R 10.5186/aasfm.2015.40xx %G en %F AFM_2015_40_1_a12