1. G. H. Hardy, Divergent Series (American Math. Soc., 1991; Komkniga, Moscow, 2006).
2. M. Riesz, “Sur la Sommation des Series de Dirichlet,” C. r. Acad. sci. A. 149, 18 (1909).
3. M. Riesz, “Une Methode de Sommation Equivalente a la Methode des Moyennes Arithmetiques,” C. r. Acad. sci. A. 152, 1651 (1911).
4. B. Kuttner, “On Discontinuous Riesz Means of Type n,” J. London Math. Soc. 37(1), 354 (1962).
5. G. H. Hardy, “Theorems Relating to the Summability and Convergence of Slowly Oscillating Series,” Proc. London Math. Soc. 8(2), 301 (1910).