1. Arend, K.H., Specker, H.: Z. Anorg. Allg. Chem. 333, 18–24 (1964)
2. Awad, K., Rudenko, N.P., Kuznecov, V.I., Gudym, L.S.: Talanta 18, 279–85 (1971)
3. Cerjuta, J.S., Bagreev, V. V., Pal’šin, E.S.: Ž. Neorg. Chim. 19, 200–04 (1974); übersetzt: Russian
4. Cerjuta, J.S., Bagreev, V. V., Pal’šin, E.S.: J. Inorg. Chem. 19, 107–10 (1974)
5. De, A.K., Rahaman, M.S.: Talanta 11, 601–06 (1964)