1. H. Perry:Sci. Am., 1974, vol. 230, pp. 19–25.
2. National Science Foundation and the Office of Coal Research:Materials Problem and Research Opportunities in Coal Conversion, Workshop held at Ohio State Univ., Columbus, OH, April 16–18, 1975. (Available from Corrosion Center, OSU, Columbus, Ohio).
3. Ind. Heat., Nov. 1974, vol. XLI, pp. 73–81, Office of Coal Research, U.S. Dept. of Interior, Washington, D.C.
4. W. T. Bakker:Refractories for Coal Conversion Process: An Engineering Approach, Twelfth Annual Sym. on Refractories, St. Louis Section of Am. Ceram. Soc., St. Louis, MO. March 1976.
5. M. S. Crowley:Am. Ceram. Soc., Bull., 1975, vol. 54, pp. 1072–74.