1. 1. “Gmelins Handbuch der Anorganishen chemie”, 8 Auf. System Nr. 21 S. 332 (1928) and Neu Bearbeitete Ergaenzungsband System Nr. 21 S. 4 (1973), Verlag Chemie, Weinheim.
2. 2. S. Fujiwara and Y. Nishimoto, Anal. Sci., 6, 771 (1990).
3. 3. “Harper’s Biochemistry”, 23rd ed., Appleton & Lange, Connecticut, 1993.
4. 4. (a) A. Shimoyama, K. Harada and K. Yanai, Chem. Lett.1985, 83.
5. 4. (b) A. Shimoyama and K. Harada, Viva Origino, 13, 13 (1985).