1. (a) For general accounts of the development of quantum theory see: Mehra J, Rechenberg H (1982) The historical development of quantum theory. Springer-Verlag, New York; Kuhn TS (1978) Black-body theory and the quantum discontinuity 1894–1912. Oxford University Press, Oxford.
2. (b) An excellent historical and scientific exposition, at a somewhat advanced level: Longair MS (1983) Theoretical concepts in physics. Cambridge University Press, Cambridge, Chapter 8–Chapter 12
3. A great deal has been written speculating on the meaning of quantum theory, some of it serious science, some philosophy, some mysticism. Some leading references are: (a) Whitaker A (1996) Einstein, Bohr and the quantum dilemma. Cambridge University Press, Cambridge. (b) Stenger VJ (1995) The unconscious quantum. Prometheus, Amherst, NY. (c) Yam P (June 1997) Scientific American, p. 124. (d) Albert DZ (May 1994) Scientific American, p. 58. (e) Albert DZ (1992) Quantum mechanics and experience. Harvard University Press, Cambridge, MA. (f) Bohm D, Hiley HB (1992) The undivided universe. Routledge, New York. (g) Baggott J (1992) The meaning of quantum theory. Oxford University Press, New York. (h) Jammer M (1974) The philosophy of quantum mechanics. Wiley, New York
4. Levine IN (2000) Quantum chemistry, 5th edn. Prentice Hall, Upper Saddle River, NJ
5. Sitzung der Deutschen Physikalischen Gesellschaft, 14 December 1900, Verhandlung 2, p. 237. This presentation and one of October leading up to it (Verhandlung 2, p. 202) were combined in: Planck M (1901) Annal Phys 4(4):553