1. R. J. Glauber:Phys. Rev.,130, 2529 (1963).
2. L. Mandel:Quantum Electronics, ed.N. Bloembergen andP. Grivet,Proceedings of Third International Congress (Paris, New York, 1964), p. 101.
3. E. Wolf:Proceedings of the Symposium on Optical Masers (New York, 1963), p. 29.
4. C. L. Mehta:Nuovo Cimento,45 B, 280 (1966).
5. C. L. Mehta:Journ. Math. Phys.,8, 1798 (1967).