1. L. F. Hatch and S. Matar, From Hydrocarbons to Petrochemicals, Gulf Publishing Co., Houston, 1981.
2. C. Ellis, Chem. Met. Eng., 23, 1230 (1920);
3. C. Ellis, Chemistry of Petroleum Derivatives, Chemical Catalog Co., New York, 1934;
4. B. T. Brooks, Ind. Eng. Chem., 27, 282 (1935).
5. P. Arthur and B. C. Pratt, US Patent 2, 571, 099 (1951);