1. R. Hagedorn andJ. Ranft:Suppl. Nuovo. Cimento.,6, 169 (1968).
2. J. Ranft:Phys. Lett.,33 B, 481 (1970).
3. R. Hagedorn andJ. Ranft: CERN-preprint, CERN-TH-1440 (1972).
4. E. Matthäus andJ. Ranft: Karl-Marx-University preprint KMU-EP-7203 (1972).
5. S. C. Frautschi:Phys. Rev. D,3, 2821 (1971).