1. S. Andersson and A. D. Wadsley, Acta Crystallogr. 14, 1245 (1961).
2. V. V. Kireev, O. V. Yakubovich, A. K. Ivanov-Shits, et al., Koord. Khim. 27(1), 34 (2001).
3. G. M. Sheldrick, SHELXL97: Program for the Refinement of Crystal Structures from Diffraction Data (University of Göttingen, Göttingen, 1997).
4. International Tables for Crystallography, Ed. by T. Hahn (Kluwer, Dordrecht, 1995, 4th ed.), Vol. A.
5. Yu. A. Pyatenko, Kristallografiya 17(4), 773 (1972) [Sov. Phys. Crystallogr. 17, 677 (1972)].