1. F.J. Dyson, Phys. Rev. 85 (1952) 861.
2. L.N. Lipativ, Leningrad Nucl. Phys. Inst. report (1976) (unpublished).
3. E. Brezin, J.C. Le Guillou and J. Zinn-Justin, Phys. Rev. D15 (1977) 1544and.
4. E. Brezin, J.C. Le Guillou and J. Zinn-Justin, Phys. Rev. D15 (1977) 1558.
5. G. Parisi, Phys. Letters 66B (1977) 167.