@article{TRSPY_1990_192_a10,
     author = {P. I. Lizorkin},
     title = {Classes of functions constructed on the basis of averages over spheres. {(The} case of spaces of {Sobolev} type)},
     journal = {Informatics and Automation},
     pages = {122--139},
     publisher = {mathdoc},
     volume = {192},
     year = {1990},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TRSPY_1990_192_a10/}
}