Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DE_1966_2_6_a9, author = {V. A. Il'in}, title = {Riesz means, {Ces\`aro} and {Poisson--Abel} summability of {Fourier} series of eigenfunctions}, journal = {Differencialʹnye uravneni\^a}, pages = {816--827}, publisher = {mathdoc}, volume = {2}, number = {6}, year = {1966}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1966_2_6_a9/} }
V. A. Il'in. Riesz means, Ces\`aro and Poisson--Abel summability of Fourier series of eigenfunctions. Differencialʹnye uravneniâ, Tome 2 (1966) no. 6, pp. 816-827. http://geodesic.mathdoc.fr/item/DE_1966_2_6_a9/