For introductionory material for science undergraduates, see Paul Davies, Quantum Mechanics (London: Routledge & Kegan Paul, 1984). and Trefil and Robert M. Hazen, The Sciences, Chs. 6-12. More technical older sources include Eugen Merzbacher, Quantum Mechanics (New York: John Wiley & Sons, 1961); Kurt Gottfried, Quantum Mechanics (New York: W. a. Benjamin, 1966); and the classic work, P. A. M. Dirac, The Principles of Quantum Mechanics, revised fourth edition (Oxford: Clarendon Press, 1958). Recent works for the general reader include Polkinghorne, Science and providence Here I am following an old favorite, David S. Saxon, Elementary Quantum Mechanics (San Francisco: Holden-Day, 1968).