1. W. Pauli,Die algemeine Prinzipien der Wellenmechanik (Handbuch der Physik, Bd. 5, Teil 1) (Springer, Berlin, 1958).
2. J. M. Jauch,Foundations of Quantum Mechanics (Addison-Wesley, Reading, Massachusetts, 1968).
3. E. Wigner, inFoundations of Quantum Mechanics: Proceedings of the International School of Physics ?Enrico Fermi,? Course IL (Academic Press, New York, 1971), pp. 1?19.
4. H. Ekstein and A. J. F. Siegert,Ann. Phys. (N.Y.) 68, 509 (1971); L. Fonda, G. C. Ghirardi, and A. Rimini,Rep. Prog. Phys. 41, 587 (1978).
5. K. Kraus,Found. Phys. 11, 547 (1981); D. Home and M. A. B. Whitaker,J. Phys. A: Math. Gen. 19, 1847 (1986); W. M. Itano, D. J. Heinzen, J. J. Bollinger, and D. J. Wineland,Phys. Rev. A 41, 2295 (1990).