1. For an introduction see: Kinzel, W.: In: Complex systemsoperational approaches. Haken, H. (ed.). Berlin, Heidelberg, New York: Springer 1985; Phys. Scr.35, 398 (1987); Amit, D., Sompolinsky, H.: In: Heidelberg Colloquium on Glassy Dynamics. In: Lecture Notes in Physics. Hemmen, J.L. van, Morgenstern, I. (eds.), Vol. 275, pp. 430, 485. Berlin, Heidelberg, New York: Springer 1987
2. Hopfield, J.J.: Proc. Natl. Acad. Sci. (USA)79, 2554 (1982)
3. A recent review of spin glasses is: Binder, K., Young, A.P.: Rev. Mod. Phys.58, 801 (1986)
4. Amit, D.J., Gutfreund, H., Sompolinsky, H.: Ann. Phys.173, 30 (1987)
5. Peretto, P.: Biol. Cybern.50, 51 (1984)