1. Becker, P. J. (1980a). In Electron and Magnetization Densities in Molecules and Crystals, NATO Advanced Studies Institute, Series B, edited by P. J. Becker, pp. 213–236. New York: Plenum.
2. Becker, P. J. (1980b). In Computing in Crystallography, edited by R. Diamond, S. Ramaseshan, and K. Venkatesan, pp. 3.01–3.24. Bangalore: Indian Academy of Sciences.
3. Becker, P. J., and Coppens, P. (1974). Acta Cryst. A30,129–147.
4. Blessing, R. H. (1984). Acta Cryst. A40, C–156.
5. Blessing, R. H. (1986a). Am. Cryst. Assoc. Meeting, Hamilton, Ontario, Canada, June 1986, Abstr. No. V4.