1. 1. Tauber, G. E. J. Math. Phys. 8, 118-123 (1967). 2. Brout, R., Englert, F. & Gunzig, E. Ann. Phys. 115, 78-106 (1978). 3. Brout, R., Englert, F. & Gunzig, E. Gen. Relativity Grav. 1, 1-5 (1979). 4. Brout, R. et al. Nucl. Phys. B170, 228-264 (1980). 5. Gunzig, E. & Nardone, P. Fund. cosm. Phys. 2,311-443 (1987). 6. Gunzig, E. & Nardone, P. Phys. Lett. B118, 324-326 (1982). 7. Gunzig, E. & Nardone, P. Gen. Relativity Grav. 16, 305-309 (1984). 8. Biran, B., Brout, R. & Gunzig, E. Phys. Lett. B125, 399-402 (1983). 9. Prigogine, I. & Geheniau, J. Proc. natn. Acad. Sci. U.S.A. 83, 6245-6249 (1986). 10. Geheniau, J. & Prigogine, I. Foundations Phys. 16, 437-445 (1986). 11. Tryon, E. P. New Scientist, 14-16 (March 1984). 12. Atkatz, D. & Pagels, H. Phys. Rev. D25, 2065-2073 (1982). 13. Vilenkin, A. Phys. Rev. D 27, 2848-2854 (1983). 14. Hartle, J. & Hawking, S. Phys. Rev. D28, 2960-2975 (1983). 15. Ford, L. H. & Parker, L. Phys. Rev. D16, 1601-1608 (1977). 16. Gunzig, E. & Nardone, P. Phys. Rev. D19, 1275-1276 (1979). 17. Spindel P. Phys. Lett. B107, 361-363 (1981). 18. Casher, A. & Englert, F. Phys. Lett. B104, 117-120 (1981). 19. Birrell, N. & Davies, P. C. W. Quantum Fields in Curved Space (Cambridge University Press, 1982). 20. Dewitt, B. S. Phys. Rep. C19, 297-357 (1975). 21. Weinberg, S. Gravitation and Cosmology Ch. 15, Section 5 (Wiley, New York, 1972).