1. M. Planck, The Theory of Heat Radiation (Dover, New York, 1959). This publication is an English translation of the second edition of Planck’s work entitled Waermestrahlung, published in 1913. A more recent republication of this work is Vol. 11 of the series The History of Modern Physics 1800–1950 (AIP, New York, 1988).
2. See, for example, Ref. [3], pp. 246 and 247, or the footnote on p. 73 in Ref. [4].
3. T. S. Kuhn, Black-Body Theory and the Quantum Discontinuity, 1894–1912 (Oxford University Press, New York, 1978).
4. L. Pauling and E. B. Wilson, Jr., Introduction to Quantum Mechanics (Dover, New York, 1985).
5. See, for example, pp. 134 and 170 in the undergraduate textbook of E. F. Taylor, An Introduction to Quantum Physics (Norton, New York, 1978) Ref. [6] or, p. 69 in the graduate textbook of Ref. [7].