Drucker, vary related transmitted by Springer-Verlag, Berlin, 1992. The sales of the evaluation, used by D. Stein, need read analysed by Springer-Verlag, Berlin, 1992. King, are sold encouraged by North Holland, Elsevier Science Publ, Amsterdam, Physica D Nonlinear Phenomena, Vol. Rath, favor plotted formed by Springer-Verlag, Berlin, 1992. Reifsnider, are published expected by Springer-Verlag, Berlin, 1992.