%0 Journal Article %A Kmit, I. %T $C^1$-smoothness of Nemytskii operators on Sobolev-type spaces of periodic functions %J Commentationes Mathematicae Universitatis Carolinae %D 2011 %P 507-517 %V 52 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/CMUC_2011__52_4_a3/ %G en %F CMUC_2011__52_4_a3