1. Weigel, F., in Handbook on the Physics and Chemistry of the Actinides Vol. III, A. J. Freeman and C. Keller eds., Elsevier Sci. Pub. (1985), pp. 243–288.
2. Bamberger, C. E., in Handbook on the Physics and Chemistry of the Actinides Vol. III, A. J. Freeman and C. Keller eds., Elsevier Sci. Pub. (1985) p. 289.
3. Leskelä, M. and Niinistö, L., in Handbook on the Physics and Chemistry of Rare Earths Vol. 9, K. A. Gschneider and L. Ewing eds., Elsevier Sci. Pub. (1987), pp. 93–139.
4. Bvrappa, K., Prog. Crystal. Growth, 13, 163 (1986). NOTE: Many page numbers of the references are those of the original Russian. papers, which are different numbers from their corresponding English translations.
5. Thomson, S. G. and Seaborg, G. T., in Prog. Nucl. Energy, Series III, Vol. 1 (F. R. Bruce, J. M. Fletcher, H. H. Hyman and J. J. Katz eds.) McGraw-Hill Book Co., New York (1956) p. 163.