1. Z.Y. Liu. Petroleum & Petrochemical Vol. 10 (2012), p.22.
2. Shell Oil Company. U.S. Patent 5739075. (1998).
3. Z.L. Wang and P. Zhuo. Technology & Economics in Petrochemicals Vol. 26 (2010), p.6.
4. X.J. Hong. Technological Development of Enterprise Vol. 30 (2011), p.32.
5. H.H. Lin. Guangzhou Chemical Industry Vol. 40 (2012), p.210.