1. For example, see: Popper, P., and Mohyuddin, I., in Special Ceramics 1964, edit. by Popper, P., 45 (Academic Press, London and New York, 1965). Kirchner, H. P., and Knoll, P., J. Amer. Ceram. Soc., 46 (6), 299 (1963).
2. Jenkins, A. C., and Chambers, G. F., Industr. Eng. Chem., 46, 2367 (1954).