1. Epstein, P. S.: Textbook of thermodynamics, p. 27–34. New York: John Wiley & Sons, Inc. 1937.
2. Bell, E. T.: Men of mathematics, p. 546. New York: Dover Publ. Inc. 1937.
3. See, for example: Niels Bohr and the development of physics (W. Pauli, ed.), p. 17–28, and footnote, p. 76. New York: Pergamon Press 1955;
4. Observation and interpretation (S. Körner, ed.), p. 41–45- New York: Academic Press, Inc. 1957; W.Heisenberg, Physics and philosophy, p. 128–146. New York: Harper & Brothers, Publ. 1958;
5. N. R. Hanson, Am. J. Phys. 27, 1 (1959);