1. Boyle, F. T., and Davies, A. (1978) British Patent Specification No. 1 502 116 of 22 Feb.
2. Desiraju, G. R. (1989)J. Chem. Soc. Chem. Comm. 179.
3. Galloy, J., and Macrae, C. (1989)PLUTO89 programme for plotting molecular and crystal structures (University of Cambridge, England).
4. Hanton, L. R., Hunter, C.A., and Purvis, D. H. (1992)J. Chem. Soc. Chem. Comm. 1134.
5. Irving, A. (1992)J. Crystallogr. Spectrosc. Res. 22, 533.