1. Beamer, W. (1948) J. Am. Chem. Soc. 70, 2979.
2. Frenz, B. A. (1985) Enraf-Nonius Structure Determination Package. College Station Texas, USA and Enraf-Nonius, Delft, Holland.
3. Hussain, M. S., and Schlemper, E. O. (1979)Inorg. Chem. 18, 1116.
4. International Table for X-ray Crystallography (1974) (Vol. IV). (Kynoch Press, Birmingham) (present distributor, Kluwer Academic Publishers, Dordrecht.)
5. Johnson, C. K. (1976)OrtepII. Report ORNL-5138. (Oak Ridge National Laboratory, Tenn.).