@article{DAN_1993_331_5_a7,
     author = {P. I. Lizorkin},
     title = {On the approximation of functions on the sphere $\sigma$. {On} the},
     journal = {Doklady Akademii Nauk},
     pages = {555--558},
     year = {1993},
     volume = {331},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1993_331_5_a7/}
}