%0 Journal Article %A P. I. Lizorkin %T Classes of functions constructed on the basis of averages over spheres. (The case of spaces of Sobolev type) %J Trudy Matematicheskogo Instituta imeni V.A. Steklova %D 1990 %P 122-139 %V 192 %I mathdoc %U http://geodesic.mathdoc.fr/item/TM_1990_192_a10/ %G ru %F TM_1990_192_a10