1. Bohr, N. (1929).Die Naturwissenschaften 18, 73.
2. Jammer, Max (1974).The Philosophy of Quantum Mechanics, Wiley-Interscience, New York.
3. Jech, Thomas J. (1971).Lecture Notes in Set Theory, Lecture Notes in Mathematics, 217, Springer-Verlag, Berlin.
4. Takeuti, G. (1975). “Boolean Valued Analysis I,” preprint.