1. Beurskens, P. T. (1984) DIRDIFDirect methods for difference structures: Technical report, Vol. 1, Toernooiveld (Ed.),Crystallography Laboratory, Nijmegen, Netherlands.
2. Britton, D., Chantooni, M. K., Jr., and Kolthoff, I. M. (1988)Acta Crystallogr. C 44, 303.
3. Cromer, D. T., and Waber, I. T. (1974)International Tables for X-ray Crystallography, Vol. IV, (The Kynoch Press, Birmingham, England), Table 2.2A.
4. Gilmore, C. J. (1984)MITHRII: An integrated direct methods computer program.J. Appl. Crystallogr. 17, 42.
5. Dobler, M. (1981)Ionophores and their structures (Wiley, New York), pp. 174?176.