1. C. D. Aliprantis and K. C. Border, Infinite Dimensional Analysis, Springer-Verlag, Berlin, third ed., 2006.
2. G. Choquet, Cours de Topologie, Masson, Paris, 1964. English translation: Topology, Wiley, New York, 1966.
3. Z. Denkowski, S. Migórski, and N. S. Papageorgiou, An Introduction to Nonlinear Analysis – Theory, Kluwer, Dordrecht, 2003.
4. P. R. Halmos, A Hilbert Space Problem Book, Springer-Verlag, New York, second ed., 1982.
5. G. H. Hardy, J. E. Littlewood, and Pólya, Inequalities, Cambridge University Press, Cambridge, 1934.