1. B. Delmon, in ?Proceedings of the 10th International Symposium on the Reactivity of Solids?, Dijon, August 1984, edited by P. Barret and L.-C. Dufour (Elsevier, Amsterdam, 1985) Part A, p. 81.
2. F. K. Lotgering,J Inorg. Nucl. Chem. 9 (1959) 113.
3. H. R. Oswald andJ. R. G�nter, in ?Proceedings of the 10th International Symposium on the Reactivity of Solids?, Dijon, August 1984, edited by P. Barret and L.-C. Dufour (Elsevier, Amsterdam, 1985) Part A, p. 101.
4. J. S. Gregg andJ. T. Hill,J. Chem. Soc. 12 (1953) 3945.
5. K. Kauffman andF. Hazel,J. Colloid Interface Sci. 51 (1975) 422.