1. Davies P. C.: 2004 ’An Overview of the Contribution of John Archibald Wheeler’, in John D. Barrow, Paul C. W. Davies, Charles L. Harper, (eds), Science and Ultimate Reality. Quantum Theory, Cosmology and Complexity, Cambridge University Press
2. Bohr, N.: 1949, Discussion with Einstein on Epistemological Problems in Atomic Physics, in Paul Schilpp (ed.),Albert Einstein: Philosopher-Scientist, pp. 201–241. Evanston, I11: Library of Living Philosophers. Cambridge University Press. Neils Bohr’s report of conversations with Einstein and Einstein’s reply.
3. Carnap, R.: 1950, ‘Empiricism, Semantics, and Ontology’ reprinted from review International du Philosophie, iv (1950), 20–40 in Richard M. Rorty (ed.),The Linguist Turn, The University of Chicago Press, 1967