1. E. Merciny and E. Duyckaerts, Bull. Soc. Chim. Belges,80, 349 (1971).
2. E. Merciny, B. Gilbert, and E. Duyckaerts, Bull. Soc. Chim. Belges,80, 617 (1971).
3. L. I. Martynenko, N. I. Pechurova, V. I. Spitsyn, Ali Khadi, K. I. Popov, and Nguen Din' Ngo, Izv. Akad. Nauk SSSR, Ser. Khim., 2659 (1970).
4. L. I. Martynenko, N. I. Pechurova, T. I. Polynova, and Nguen Din' Ngo, Zh. Neorgan. Khim.,14, 3005 (1969).
5. N. D. Mitrofanova, L. I. Martynenko, and A. I. Grigor'ev, Zh. Neorgan. Khim.,9, 320 (1964).