1. E. M. M. EWAIS: J. Ceram. Soc. Jpn., 2004, vol. 112, pp. 517-32.
2. C.F. Cooper, I.C. Alexander, and C.J. Hampson: Br. Ceram. Trans., 1985, vol. 84, pp. 57-62.
3. X. Peng, L. Li, and D. Peng: Refractories, 2003, vol. 37, pp. 355-7.
4. Z. Boquan, Z. Wenjie, and Y. Yashuang: Refractories, 2006, vol. 40, pp. 90-5.
5. S. Tamura, T. Ochiai, S. Takanaga, T. Kanai, and H. Nakamura: Proceedings of the 8th UNITECR-03, Osaka, Japan, 2003, pp. 19–22.