1. see e.g. R. Hagedorn, ‘The Long Way to the Statistical Bootstrap Model’, these proceedings.
2. see e.g. A. I. Bochkarev, Phys. Lett. B254:165 (1991) and references therein.
3. see ‘Electroweak physics and the Early Universe’ Eds. F. Freiré and J. Romão, Plenum Publ. Corp., N. Y, in press, for a recent account of the state of art.
4. M. E. Shaposhnikov, Nucl. Phys. B287:757 (1987).
5. M. Dine, R. G. Leigh, P. Huet, A. Linde and D. Linde, Phys. Rev. D46:550 (1992).