1. Chapter 5.
2. Atkins, P.W., and Symons, M.C.R.: 1967, The Structure of Inorganic Radicals (Elsevier, Amsterdam).
3. Wertz, J.E., and Bolton, J.R.: 1972, Electron Spin Resonance (McGraw-Hill, New York).
4. Atherton, N.M.: 1973, Electron Spin Resonance (Halsted Press, London).
5. Lewis, G.N., and Lipkin, D.: 1942, J. Amer. Chem. Soc. 64, p. 2801.