1. J. Andrade e Silva and M. Andrade e Silva,C. R. Acad. Sci. (Paris) 290, 501 (1980).
2. A. Garuccio, V. Rapisarda, and J. P. Vigier,Phys. Lett. A 90, 17 (1982).
3. G. Tarozzi,Lett. Nuovo Cimento 42, 438 (1985).
4. F. Selleri,Lett. Nuovo Cimento 1, 908 (1969);Found. Phys. 12, 1087 (1982).
5. A. Gozzini, ?On the possibility of realizing a low-intensity interference experiment with a determination of the particle trajectory,? inThe Wave-Particle Dualism, S. Dineret al., eds. (Reidel, Dordrecht, 1984); R. Giovanelli, ?Detection of empty waves by means of photon correlations in amplified light pulses,? inMicrophysical Reality and Quantum Formalism, A. van der Merwe, F. Selleri, and G. Tarozzi, eds. (Reidel, Dordrecht, 1987); H. Rauch, inNew Techniques and Ideas in Quantum Measurement Theory, D. Greenberger, ed. (New York Academy of Sciences, New York, 1986).