1. R. Colton,The Chemistry of Rhenium and Technetium (Wiley, New York, 1965).
2. R. D. Peacock,The Chemistry of Technetium and Rhenium (Elsevier, New York, 1966).
3. C. Keller and B. Kanellakopulos,Radiochim. Acta 1, 107 (1963).
4. R. D. Peacock,The Chemistry of Technetium and Rhenium (Elsevier, New York, 1966), p. 33.
5. G. E. Boyd,J. Chem. Ed. 36, 3 (1959).