1. For a general reference see S. S.Isied in, Metal Ions in Biological Systems, ed. H. Sigel, Marcel Dekker, New York, 1991, vol. 27, pp. 1–56.
2. J. V. Beitz and J. R.Miller, In Tunneling in Biological Systems, Academic Press, New York, 1979, p. 269–280.
3. Modifications of transition-metal reaction patterns through the manipulation of superexchange couplings