1. G. Natta and I. Pasquon, Adv. Catal, 11, 2 (1959).
2. A. Zambelli, P. Locatelli, and E. Rigamonti, Macromolecules, 12, 156 (1979).
3. P. Longi, G. Mazzanti, A. Roggero, and M. Lachi, Makromol. Chem., 61, 63 (1963).
4. M. Tobin, J. Phys. Chem., 64, 216 (1960).
5. M.N. Berdnikova, Y.V. Kissin, and N.M. Chirkov, Vysokomol. Soedin., 5, 63 (1963).