%0 Journal Article %A Z. Ditzian %T Optimality of the range for which equivalence between certain measures of smoothness holds %J Studia Mathematica %D 2010 %P 271-277 %V 198 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/sm198-3-6/ %R 10.4064/sm198-3-6 %G en %F 10_4064_sm198_3_6