1. E. Nelson:Phys. Rev.,150, 1079 (1966).
2. SeeG. Cavalleri:Phys. Rev. D,23, 363 (1981), where also a criticism of stochastic mechanics and of the paper of ref. (2) is given. An extension of eq. (1) to a free charge has been obtained byA. Rueda:Phys. Rev. A,23, 2020 (1981).
3. For a review of the results of SED seeM. Surdin:Ann. Inst. Henry Poincaré,15, 203 (1971). See alsoT. H. Boyer:Phys. Rev. B,11, 790, 809 (1975).
4. For the most recent achievements seeT. H. Boyer:Phys. Rev.,18, 1238 (1978);P. Claverie andS. Diner:Inst. J. Quantum Chem.,2, Suppl. 1,41 (1977).
5. P. Claverie andS. Diner:Int. J. Quantum Chem.,42, Suppl. 1, 41 (1977);P. Claverie:Proceedings of Einstein Centennial Symposium on Fundamental Physios, Bogota, 1979, edited byS. M. Moore, A.M. Rodriguez-Vargas, A. Rueda andG. Violini (Universidad de los Andes, Bogotà, 1979); inBynamical Systems and Microphysics, edited byA. Blaquiere, F. Fer andA. Marzollo, CISMCourses and Lectures No. 261 (Springer-Verlag, Berlin, 1980), p. 11;P. Claverie, L. Pesquera andF. Soto:Phys. Lett. A,80, 113 (1980);T. W. Marshall andP. Claverie:J. Math, Phys.,21, 1819 (1980).