1. Handbook of the philosophy of science;P Apostoli,2009
2. Benacerraf, P.: What numbers could not be. Philos. Rev. 74(1), 47–73 (1965)
3. Benacerraf, P., Putnam, H.: Introduction. In: Benacerraf, P., Putnam, H. (eds.) Philosophy of Mathematics: Selected Readings, 2nd edn, pp. 1–39. Cambridge University Press, Cambridge (1983)
4. Bernays, P.: On platonism in mathematics. In: Benacerraf, P., Putnam, H. (eds.) Philosophy of Mathematics: Selected Readings, 2nd edn, pp. 258–271. Cambridge University Press, Cambridge (1983)
5. Bernays, P.: Hilbert, David (1862–1943). In: Borchert, D.M. (ed.) Encyclopedia of Philosophy, vol. 4, 2nd edn, pp. 357–366. Macmillan Reference USA, Detroit (2006)