1. For more details see H. Born and E. Wolf: Principles of Optics (Oxford: Pergamon Press, Ltd.; New York: The Macmillan Comp., 2nd ed. 1964) and L. Mandel and E. Wolf: Rev. Mod. Phys. 37, 231 (1965), whom we will follow closely. The latter paper contains also a very detailed list of references both of classical and quantum theoretical treatments of coherence up to 1964.
2. M. Beran and G.B. Parrent: Theory of Partial Coherence. Engle-wood Cliffs, New Jersey: Prentice Hall 1964.
3. D. Gabor: J. Inst. Elec. Eng. (London) 93, 429 (1946).
4. R. Hanbury Brown and R.O. Twiss: Nature 177, 27 (1956). This experiment has recently been repeated by W. Martienssen and E. Spiller: Am. J. Phys. 32, 919 (1964) using their “pseudothermal source”.
5. For more details see: R.J. Glauber, in: Quantum Optics and Electronics (C. de Witt, A. Blandin, and C. Cohen-Tannoudji, eds.). New York: Gordon & Breach 1965.