1. V. N. Gribov, J. Nyiri, Supercritical Charge in Bosonic Vacuum LU-TP-91-15, unpublished.
2. W. Greiner, B. Müller, J. Rafelski,Quantum Electrodynamics of Strong Fields, Springer-Verlag, Berlin, 1981.
3. M. Oleszczuk, J. Polonyi, Canonical versus Grand Canonical Ensembles in QCD, submitted toZ. Phys.; M. Faber, O. Borisenko, G. Zinovjev, Triality in QCD at Zero and Finite Temperature: a New Direction, to appear inNucl. Phys.
4. S. Mandelstam,Phys. Rep.
23C (1976) 245; G. t’ Hooft,Nucl. Phys.
B190 (1981) 455; H. B. Nielsen, P. Olesen,Nucl. Phys.
B61 (1976) 45.
5. K. Johnson, L. Lellouch, J. Polonyi,Nucl. Phys.
B367 (1991) 675.