1. E. H. Wiekenga, E. E. Havinga, and K. H. Boswijk, Advances in Inorganic Chemistry and Radiochemistry, Vol. 3, Academic Press Inc., New York, 1961, pp. 133–169.
2. W. F. Zelezny and N. C. Baenziger, J. Am. Chem. Soc.
74: 6151 (1952).
3. R. W. G. Wyckoff, J. Am. Chem. Soc.
42: 1100 (1920).
4. H. A. Tasman and K. H. Boswijk, Acta Cryst. 8: 59 (1955).
5. S. Siegel, Acta Cryst. 10: 380 (1957).