1. P. F. Becher,J. Amer. Ceram. Soc. 74 (1991) 255.
2. S. S?miya andY. Hirata,Amer. Ceram. Soc. Bull. 70 (1991) 1624.
3. R. D. Nixon, S. Chevacharoenkul,R. F. Davis andT. n. Tiegs, in ?Mullite and mullite matrix composites,? edited by S. S?miya, R. F. Davis and J. A. Pask (The American Ceramic Society, Westerville, OH, 1990) p. 579.
4. R. R. Tummala,J. Amer. Ceram. Soc. 74 (1991) 895.
5. G DE Portu andJ. W. Henney,Br. Ceram. Trans. J. 83 (1984) 69.