1. Sheldrick, G.M., SHELXL-93. Program for the Refinement of Crystal Structures, Göttingen (Germany): Univ. of Göttingen, 1997.
2. Allen, F.M. and Kennard, O., Watson et al., J. Chem. Soc., Perkin. Trans., 1987, no. 11, p. 51.
3. Desjardins, S.R., Penfield, K.W., Cohen, S.L., et al., J. Am. Chem. Soc., 1983, vol. 105, no. 14, p. 4590.
4. Liver, A.B.P., Inorganic Electronic Spectroscopy, Amsterdam: Elsevier, 1984, part 1.
5. Solomon, E.I., Baldwin, M.J., and Lowery, M.D., Chem. Rev., 1992, vol. 92, no. 4, p. 521.