1. P. S. Rogers, J. Williamson, J. F. Bell andM. Campbell, in ?Energy Conservation in Industry ? Applications and Techniques?, edited by A. S. Strub and H. Ehringer (VDI, Verlag, Dusseldorf, 1984) p. 280.
2. S. Carter, C. B. Ponton, R. D. Rawlings andP. S. Rogers,J. Mater Sci. 23 (1988) 2622.
3. C. B. Ponton, R. D. Rawlings andP.S. Rogers, in ?Proceedings of the Conference on Special Ceramics? (The Inst. Ceramics, London, December 1986) p. 229.
4. ASTM C338-73, part 17 (1975) 287.
5. P. W. Mcmillan, in ?Glass-Ceramics? 2nd edn. (Academic Press, London, 1979).