1. Tariff, U. S. Commission Reports.
2. Leonard, E. C. 1971.Vinyl and Diene Monomers, Vol. 24, 495New York: Interscience (Wiley). Part 2 (High Polymers)
3. Stanford Research Institute. Process Economics Report No. 38, October, 1967 was used as the original basis for up-dating to larger volumes and current operating and capital costs