1. E. Fluck, Gmelin Handbuch Der Anorganischen Chemie, B2, (Berlin Achte Völligneu bearbeitete Auflage, Springer-Verlag, 1984), pp. 280–315.
2. R.C. Weast and M.J. Astle, ed., CRC Handbook of Chemistry and Physics, 61st ed. (Boca Raton, Florida: CRC Press, 1980), pp. B–141 and B-153.
3. D.M. Chizhikov and V.P. Shchastlivyi, Selenium and Selenides (London: Collet′s Publisher Ltd., 1968), pp. 104–107.
4. S. Kuwano, “Separation of Selenium Impurities from Sulfur,” Japanese patent 6921, 407 (12 September 1969).
5. S. Kuwano, “Separating Selenium Impurities from Sulfur,” Japanese patent 6921, 408 (12 September 1969).