1. T. Sugama and N.R. Carciello, J. Am. Ceram. Soc. (in press).
2. Joint Committee on Powder Diffraction Standards, Card 24–27.
3. The infra-red Spectra of Complex Molecules;Bellamy,1975
4. Infrared Spectra of Inorganic Compounds;Nyquist,1971
5. Recent progress in the chemistry, crystal chemistry and structure of the apatites