1. Edwards, S.F., Anderson, P.W.: J. Phys. F5, 965 (1975)
2. For recent review see: a) Binder, K.: in: Festkörperprobleme (Advances in Solid State Physics), edited by J. Treusch, vol. XVII, p. 55. Braunschweig: Vieweg 1977 b) Binder, K., Stauffer, D.: in: Monte Carlo Methods in Statistical Physics, edited by K. Binder. Berlin-Heidelberg-New York: Springer (in press) c) Murani, A.P.: J. Appl. Phys.49, 1604 (1977) d) Fischer, K.H.: Physica86?88B, 813 (1977)
3. Thouless, D.J., Anderson, P.W., Palmer, R.G.: Phil. Mag.35, 593 (1977)
4. a) Binder, K., Schröder, K.: Sol. State Comm.18, 1361 (1976) b) Binder, K., Schröder, K.: Phys. Rev. B14, 2142 (1976)
5. a) Binder, K.: Physica86?88B, 871 (1977) b) Binder, K.: Z. Physik B26, 339 (1977)