1. US Patent 4110352, 1979.
2. US Patent 4203910, 1981.
3. US Patent 4101560, 1979.
4. Markevich, V.S., Ul’yanova, V.N., and Loginova, V.A., Neftepererab. Neftekhim., 1979, no. 11, p. 47.
5. Trach, Yu., Nykypanchuk, M., and Komarenska, Z., Pol. J. Chem., 2002, no. 76, p. 1323.