Voir la notice de l'article provenant de la source Math-Net.Ru
@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/} }
P. I. Lizorkin; S. M. Nikol'skii. Approximation on the sphere in $L_2$. Doklady Akademii Nauk, Tome 271 (1983) no. 5, pp. 1059-1063. http://geodesic.mathdoc.fr/item/DAN_1983_271_5_a7/