1. J. P. Hogan, and R. L. Banks, Belgian Pat. 530,617 (1955U.S. Patents 2,825,721(1958); 2,846,425 (1958); 2,951,816 (1960)
2. Marlex Catalyst Systems
3. History of Polyolefins
4. G. C. Bailey, and James A. Reid, U. S. Patents 2,381,198 (19452,581,228 (1952); 2,606,940 (1952)