1: Greenwood,N.N., Earnshaw,A. Chemistry of the elements
2nd edition (1997) Edited by Greenwood,N.N., Earnshaw,A. pp. 1-1340, Butterworth-Heinemann. Oxford. Great Britain

2: CRC Handbook of Chemistry and Physics
75th edition (1994) Edited by Lide,D.R. , CRC Press Inc. Boca Raton, USA

3: Merck. ChemDAT The Merck Chemical Database Ver. 1.1.5

4: The Merck Index
12th edition (1996) Edited by Budavari,S., Merck Research Laboratories, USA

5: General chemistry
7th edition (1984) Edited by Holtzclaw, Jr.,H.F., Robinson,W.R. & Nebergall,W.H. pp. 1-932. D.C. Heath and Company. Lexington