1. C.J. Ballhausen, “Introduction to Ligand Field Theory,” McGraw-Hill, New York, 1962.
2. B.R. McGarvey, in “Transition Metal Chemistry,” Vol. 3, edited by R.L. Carlin, Marcel Dekker, Inc., New York, 1966, p. 90.
3. F.A. Cotton and G. Wilkinson, “Advanced Inorganic Chemistry,” Ed. 3, J. Wiley and Sons, New York, 1972.
4. A. Abragam and B. Bleaney, “Electron Paramagnetic Resonance of Transition Ions,” Oxford University Press, Oxford, 1970.
5. J.W. Orton, “Electron Paramagnetic Resonance,” Iliffe Books, Ltd., London, 1968.