1. Previous reviews of this subject include Refs. 2–8
2. K. Binder, in Fluctuations,Instabilities and Phase Transitions (T.Riste,ed.)p. 53, Plenum, New York 1975.
3. K. Binder and D. Stauffer, Adv.Phys. 25, 343 (1976).
4. K. Binder, J.phys.(Paris) 41,C4–51(1980).
5. J.S. Langer, in Systems Far from Equilibrium (L.Garrido, ed.)p.l, Springer, Berlin 1980.