1. For a recent review see e.g. H. Satz, Plenary Talk at the ECFA Workshop on Large Hadron Colliders, Aachen, CERN preprint TH.5917/90 (1990).
2. For a recent review see e.g. A. Ukawa, Plenary talk at the 25th International Conference on High Energy Physics, Singapore, preprint UTHE-P213 (1990)
3. P. Gerber and H. Leutwyler, Nucl. Phys. B321 (1989) 387.
4. A. Barducci, R. Casalbuoni, S. De Curtis, R. Gatto and G. Pettini, Phys. Rev. D41 (1990) 1610.
5. U. Heller and F. Karsch, Nucl. Phys. B251[FS13] (1985) 254; B258 (1985) 29; F. Karsch, CERN preprint TH.4851/87 (1987); F. Karsch, CERN preprint TH.5498/89 (1989) to appear in ”Quark Gluon Plasma” R. C. Hwa ed. World Scientific.