1. E. Gava, R. Jengo, and C. Omero, Phys. Lett.,81, No. 2, 187–189 (1979).
2. S. V. Chervon, in: International Conference on Astrophysics and Cosmology, Abstracts, December 20–23, 1993, Saha Institute of Nuclear Physics, Calcutta, India (1993), p. 44.
3. S. V. Chervon, Izv. Vyssh. Uchebn. Zaved., Fiz., No. 5, 114–119 (1995).
4. J. P. Mucket and S. Gottlober, in: Proceedings of the Sixth APRMA, August 16–20, 1993, IUCAA, Puna, India (in J. Astrophys. Astron.).
5. P. Peter, D. Polarski, and A. A. Starobinsky, Preprint YITP/V-94-6, DAMTP-R-94/20, Astroph/940 3037, April (1994).