1. Abian, A.: The Theory of Sets and Transfinite Arithmetic. W.B. Saunders Co., London (1965)
2. Handbook of the philosophy of science;D Bonevac,2009
3. Burgess, J.P.: Why I Am not a nominalist. Notre Dame J. Formal Logic. 24(1), 93–105 (1983)
4. Chihara, C.S.: Ontology and the Vicious Circle Principle. Cornell University Press, Ithaca (1973)
5. Chihara, C.S.: Constructibility and Mathematical Existence. Clarendon Press, Oxford (1990)