1. J. Boor, Jr., “Ziegler-Natta Catalysts and Polymerizations”, Academic Press, Inc., New York, 1979.
2. E. J. Vandenberg and B. C. Repka, “Ziegler-Type Polymerizations”, in C. E. Schildknecht, Ed., “Polymerization Processes”, Wiley, 1977, Chapter 11.
3. C. C. Price and M. Osgan, J. Amer. Chem. Soc. 78, 4787 (1956).
4. M. E. Pruitt and J. M. Baggett (to Dow Chemical Co.), U.S. Patent 2,706,181, filed June 6, 1952, issued April 12, 1955.
5. E. J. Vandenberg, J. Polym. Sci., Part Al, 7 525 (1969).