1. Handbook of Chemicals Production Processes;Malow,1986
2. BP Amoco, http://www.bpamoco.com, press release, 29 May, 1997.
3. U.S. Patents 4,760,154 (1988), 4,835,125 (1989), 4,837,191 (1989), and 4,843,055 (1989), assigned to the Standard Oil Company (Ohio).