1. P. K. Karantn and L. R. Laksmanan, Indian J. Technol., 310?304 (1972).
2. J. Maréchal and P. Radzitsky, J. Inst. Pet.,46, No. 434, 33?41 (1960).
3. R. A. Martirosov, G. S. Kaganer, B. P. Filatov, et al., Neftepererab. Neftekhim. (Moscow), No. 11 (1972).
4. W. Kisilow and C. Kajdas, Fette Seifen Anstrichm.,1, 4?9 (1971).
5. Nonstoichiometric Compounds (R. Ward, et.), Adv. Chem. Ser. No. 39, Amer. Chem. Soc., Washington D.C. (1963) [Russian translation (1971), p. 607].