1. Dunford N., “An individual ergodic theorem for non-commutative transformations,” Acta Sci. Math. (Szeged), vol. 14, 1–4 (1951).
2. Zygmund A., “An individual ergodic theorem for non-commutative transformations,” Acta Sci. Math. (Szeged), vol. 14, 103–110 (1951).
3. Krengel U., Ergodic Theorems, De Gruyter, Berlin and New York (1985) (De Gruyter Studies in Mathematics; vol. 6).
4. Dunford N. and Schwartz J.T., Linear Operators. Vol. 1: General Theory, John Wiley and Sons, New York (1988).
5. Karagulyan G.A., Lacey M.T., and Martirosyan V.A., “On the convergence of multiple ergodic means,” New York J. Math., vol. 28, 1448–1462 (2022).