1. Rundle, R.E., Baenzinger, N.C., Wilson, A.S., McDonald, R.A.: J. Am. Chem. Soc. 70 (1949) 99.
2. D'Eye, R.W.M., Sellman, P.G., Murray, J.R.: J. Chem. Soc. III (1952) 2555.
3. Wait, E.: J. Inorg. Nucl. Chem. 1 (1955) 309.
4. Ballestracci, R., Bertaut, E.F., Pauthenet, R.: J. Phys. Chem. Solids 24 (1963) 487.
5. Kovba, L.M., Vidavskii, L.M., Lavut, E.G.: Zh. Strukt. Khim. 4 (1963) 627.