1. K. A. Golubjatnikov, G. C. Stangle and R. M. Spriggs, Amer. Ceram. Soc. BulL. 72 (1993) 96.
2. Y. Sheng, M. Liu and Z. Guo, Int J. SHS 1 (1993) 69.
3. O. Odawara, Mater. Manuf Processes 8 (1993) 203.
4. Hui-Ping Duan, Yin Sheng, Mu Liu and Lai Hoyi, Proceedings of the 94' Autumn Meeting of China Materials Research Society, (to be published).