1. Taylor, M. and Ewing, R.C., Acta Crystallogr., Sect. B, 1978, vol. 34, pp. 1074–1075.
2. Mokeeva, V.I. and Golovastikov, N.I., Dokl. Akad. Nauk SSSR, 1966, vol. 167, no. 5, pp. 1131–1134.
3. Richard, P. and Perrault, G., Acta Crystallogr., Sect. B, 1972, vol. 28, pp. 1994–1999.
4. Kabalov, Yu.K., Sokolova, E.V., Pautov, L.A., and Schneider, J., Kristallografiya, 1998, vol. 43, no. 4, pp. 632–636.
5. Szymanski, J.T., Owens, D.R., Roberts, A.C., et al., Can. Mineral., 1982, vol. 20, pp. 59–63.