1. B.A. Frenz and Associates, Inc. (1982), SDP Struc-ture Determination Package. College Station, Texas, USA.
2. Clark, JR., Appleman, D.E. and Papike, J.J. (1969), Crystal-chemical characterization of clinopyroxenes based on eight new structure refinements. Mineral. Soc. Am. Spec. Pap., 2, 31-50.
3. Fukunaga, O., Yamaoka, S., Endo, T., Akaishi, M. and Kanda, H. (1979), Modification of belt-like high pressure apparatus. High-pressure Sci. Technol., 1, 846-852.
4. International Tables for X-ray Crystallography (1974). Vol. IV. Birmingham: Kynoch Press. (Present distributor Kluwer Academic Publishers, D. Reidel Dordrecht.)
5. Kirkpatrick, R.J. (1988), in Spectroscopic methods in mineralogy and geology, edited by F.C. Hawthorne, Reviews in Mineralogy vol. 18 (Mineralogical Society of America, Washington, D.C.20006 U.S.A.) P. 349.