1. British Patent 300,703, Aug. 11, 1927, to I. G. Farbenind. A.-G.
2. British Patent 302,253, June 9, 1927, to I. G. Farbenind. A.-G.
3. Bocharova, E. M., Dolgov, E. N., and Petrova, Yu. N., J. Chem. Ind. (Moscow), 1935,12, 1249.
4. Ellis, Carleton, “Hydrogenation of Organic Substances,” D. Van Nostrand Co., Inc., 1930.
5. Ellis, Carleton, “The Chemistry of Petroleum Derivatives,” Vol. 1 and 2, Reinhold Publishing Corp., 1934 and 1937.