1. Brudno, A.: Summation of Bounded Sequences by Matrices (in Russian). Recueil Math. (Mat. Sbornik), N. S.16, 191?247 (1945).
2. Lorentz, G. G.: A Contribution to the Theory of Divergent Sequences. Acta Math.80, 167?190 (1948).
3. Goffman, Casper, andG. M. Petersen: Consistent Limitation Methods. Proc. Amer. Math. Soc.1956, 367?269.
4. Petersen, G. M.: Almost Convergence and Well Distributed Sequences: Quart. J. Math. (Oxford) (to appear).
5. Schur, I.: �ber lineare Transformationen in der Theorie der unendlichen Reihen. J. reine u. angew. Math.151, 79?111 (1921).