1. Matsunaga K (2008) Next generation polyolefins, vol 1. Sankeisha, Nagoya, p 84
2. Albizzati E, Giannini U, Collina G, Noristi L, Resconi L (1996) In: Moore EP Jr (ed) Polypropylene handbook. Hanser-Gardner, Cincinnati, p 11
3. Natta G (1995) J Polym Sci 16:143
4. Natta G (1955) J Am Chem Soc 77:1707
5. Hermans JP, Henrioulle P (1972) Process for the preparation of a Ziegler–Natta type catalyst. German Patent 2,213,086, to Solvay & CIE