[1] R. J. Glauber, Phys. Rev. 130, 2529 (1963).
[2] E. C. G. Sudarshan, Phys. Rev. Lett. 10, 277 (1963).
[3] J. R. Klauder, Phys. Rev. lett. 16, 534 (1966).
[4] C. L. Metha and E. C. G. Sudarshan, Phys. Rev. 138, B274 (1965).
[5] F. T. Arecchi, E. Gatti, and A. Sona, Phys. Lett. 20, 27 (1966).
[6] M. Born and E. Wolf, Principles of Optics (5th ed.) (Pergamon Press, London, 1975).
[7] R. Loudon, The Quantum Theory of Light (Clarendon, Oxford, 1978), p. 100.
[8] P. Grangier, G. Roger, and A. Aspect, Europhys. Lett. 1, 173 (1986).
[9] P. A. M. Dirac, The Principle of Quantum Mechanics (2th Ed.) (Clarendon, Oxford, 1935).
