1. P. A. H. Brooker, Asplund operators and the Szlenk index, J. Operator Theory 68 (2012), 405–442.
2. G. Lancien, A survey on the Szlenk index and some of its applications, Rev. R. Acad. Cienc. Exactas Fís. Nat. Ser. A Math. RACSAM 100 (2006), no. 1–2, 209–235.
3. B. Beauzamy, Opérateurs de type Rademacher entre espaces de Banach, Sém Maurey–Schwartz, Exposés 6 et 7, École Polytéchnique, Paris, 1975/76.
4. B. Beauzamy, Opérateurs uniformément convexifiants, Studia Math. 57 (1976), no. 2, 103–139.
5. R. M. Causey, An alternate description of the Szlenk index with applications, Illinois J. Math. 59 (2015), no. 2, 359–390.