@article{DAN_1983_271_5_a7,
     author = {P. I. Lizorkin and S. M. Nikol'skii},
     title = {Approximation on the sphere in $L_2$},
     journal = {Doklady Akademii Nauk},
     pages = {1059--1063},
     publisher = {mathdoc},
     volume = {271},
     number = {5},
     year = {1983},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1983_271_5_a7/}
}