1. K. Nakanishi and N. Soga, J. Am. Ceram. Soc. (in press).
2. K. Nakanishi and N. Soga, submitted to J. Am. Ceram. Soc.
3. K. Nakanishi and N. Soga, this issue, p. 14.
4. K. Nakanishi and N. Soga, submitted to J. Non-Cryst. Solids (part 3).
5. K. Nakanishi and N. Soga, submitted to J. Non-Cryst. Solids (part 4).