1. W. Strohmeier and D. Hobe, Z. Naturforseh.,18b, 981 (1963).
2. V. I. Losilkina, N. K. Baranetskaya, V. N. Setkina, and D. N. Kursanov, Zh. Koord. Khim.,5, 1816 (1979).
3. W. Strohmeier and H. Helmann, Chem. Ber.,97, 1877 (1964).
4. M. Heberhold, K. Leonhard, and A. Geier, Chem. Ber.,110, 3279 (1977).
5. D. N. Kursanov, V. N. Setkina, and N. I. Pyshnograeva, Izv. Akad. Nauk SSSR, Ser. Khim., 878 (1984).