1. H.W. Scheeline, SRI Report 33B (1977) 73;
2. Y.C. Yen and T.H. Vanden Bosch, SRI Report 33A (1973) 35;
3. Y.C. Yen, SRI Report 33 (1967) 91.
4. B. Delmon, P.A. Jacobs and G. Poncelet, eds.,Preparation of Catalysts II (Elsevier, Amsterdam, 1979) p. 293.
5. E.H. Lee, Catal. Rev. 8 (1973) 285.