1. S. A. Argyros, S. Mercourakis and A. Tsarpalias, Convex unconditionality and summability of weakly null sequences, Israel J. Math. 107 (1998), 157–193.
2. W. T. Gowers and B. Maurey, The unconditional basic sequence problem, J. Amer. Math. Soc. 6 (1993), 851–874.
3. G. Androulakis and K. Beanland, A hereditarily indecomposable asymptotic $\ell_2$ Banach space, Glasg. Math. J. 48 (2006), 503–532.
4. W. T. Gowers, A remark about the scalar-plus-compact problem, Convex geometric analysis (Berkeley, CA, 1996), Math. Sci. Res. Inst. Publ., vol. 34, Cambridge Univ. Press, Cambridge, 1999, pp. 111–115.
5. D. Alspach and S. A. Argyros, Complexity of weakly null sequences, Diss. Math. 321 (1992), 1–44.