@article{1077492650, author = {Forsythe, G. E.}, title = {Riesz summability methods of order $r$ , for $\mathcal{R}(r)<0$}, journal = {Duke Math. J.}, volume = {8}, number = {1}, year = {1941}, pages = { 346-349}, language = {en}, url = {http://dml.mathdoc.fr/item/1077492650} }
Forsythe, G. E. Riesz summability methods of order $r$ , for $\mathcal{R}(r)<0$. Duke Math. J., Tome 8 (1941) no. 1, pp. 346-349. http://gdmltest.u-ga.fr/item/1077492650/