1. P. C. Kong and E. Pfender, in ?Heat transfer in thermal plasma processing?, Heat Transfer Division Vol. 161 (American Society of Mechanical Engineers, New York, 1991) p. 1.
2. I. B. Cutler, US Patent 3754076 (August 1973).
3. A. K. Ray, G. Mahanty and A. Ghose, J. Mater. Sci. Lett. 10 (1991) 227.
4. M. Patel, Silicates Industriels 55 (1/2) (1991) 33.
5. S. R. Nutt, J. Amer. Ceram. Soc. 71 (1988) 149.