1. Zel'dovich, Ya, B. (1967).Sov. Phys. JETP Lett.,6, 316; (1968),Sov. Phys. Usp.,11, 381.
2. Linde, A. D. (1974).JETP Lett.,19, 183; (1980),Phys. Lett. B,93, 394; (1982),Phys. Lett. B,108, 386.
3. Dicke, R. H. (1964). InGravitation and Relativity, Chiu, H. Y., and Hoffmann, W. F., ed. (Benjamin, New York), p. 128.
4. Brans, C., and Dicke, R. H. (1961).Phys. Rev.,124, 925.
5. Gamov, G. (1970).My World Line (Viking, New York), p. 44.