1. K. Fischer,Phys. Stat Sol. (b) 116:357 (1983).
2. R. Rammal and J. Souletie, inMagnetism of Metals and Alloys, M. Cyrot, ed. (North-Holland, Amsterdam, 1982).
3. G. Toulouse,Commun. Phys. 2:115 (1977).
4. A recent discussion of ?what is a spin glass? is given by D. Sherrington, inProceedings of Heidelberg Colloquium on Spin Glasses (Springer, Berlin, to be published).
5. See, for instance, the discussion in Ref. 2.