1. R.D. Mullineaux, (Shell), Belg. Pat., 603,820 (1961);
2. L.H. Slaugh and R.D. Mullineaux (Shell), Belg. Pat., 608, 408 (1961);
3. US. Pat, 3, 239, 569 (1966);
4. L.G. Canell, L.H. Slaugh and R.L. Mullineaux, (Shell), Ger. Pat., 1,186,455 (1965).
5. L.H. Slaugh and R.L. Mullineaux, J. Organomet. Chem., 13 (1968) 469.