1. A. Haaland, Angew. Chem., Int. Ed. Engl., 1989, 28, 992.
2. K. Wade and A.J. Banister, in Comprehensive Inorganic Chemistry, ed. J.C. Bailar, Jr., H.J. Emeléus, R. Nyholm and A.F. Trotman-Dickenson, Vol. 1, Pergamon, Oxford, 1973, p. 993.
3. N.N. Greenwood, Adv. Inorg. Chem. Radiochem., 1963, 5, 91.
4. I.A. Sheka, I.S. Chaus and T.T. Mityureva, The Chemistry of Gallium, Elsevier, Amsterdam, 1966.
5. A.G. Lee, The Chemistry of Thallium, Elsevier, London, 1971.