Beanland, Kevin, and Ryan M. Causey. “Quantitative Factorization of Weakly Compact, Rosenthal, and $\xi$-Banach-Saks Operators”. Mathematica Scandinavica, vol. 123, no. 2, Sept. 2018, pp. 297-19, https://doi.org/10.7146/math.scand.a-105124.