Voir la notice de l'article provenant de la source Math-Net.Ru
@article{MZM_1990_48_5_a0, author = {V. A. Andrienko}, title = {Rate of approximation of orthogonal series by {Riesz} means}, journal = {Matemati\v{c}eskie zametki}, pages = {3--14}, publisher = {mathdoc}, volume = {48}, number = {5}, year = {1990}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/MZM_1990_48_5_a0/} }
V. A. Andrienko. Rate of approximation of orthogonal series by Riesz means. Matematičeskie zametki, Tome 48 (1990) no. 5, pp. 3-14. http://geodesic.mathdoc.fr/item/MZM_1990_48_5_a0/