1. R. Hagedorn, Suppl. Nuovo Cimento 3, 147 (1965) (Part I)
2. R. Hagedorn, J. Ranft, Nuovo Cimento Suppl. 6, 169 (1968) (Part II)
3. R. Hagedorn, Nuovo Cimento Suppl. 6, 311 (1968) (Part III), see also Chapters17, 23 and 25
4. A.H. Rosenfeld, A. Barbaro-Galtieri, J. Podolsky, L.R. Price, P. Söding, C.G. Wohl, M. Roos, W.J. Willis, Rev. Mod. Phys. 39, 1 (1967)
5. T.T. Wu, C.N. Yang, Phys. Rev. 137, B708 (1965)