1. LIU SHI-YOU, J. Non-Ferrous Metals. 2 (1999)30.
2. M. F. MCNAMARA, J. A. SLATTERY and A. F. WITT, US Patent 4,828,608.
3. OKAMOTO HIDENORI and TAKEBA YASHI KAZUAKI, US Patent 5,543,031.
4. M. S. SU, J. S. GENTRY and C. B. BOSS, J. Electrochem Soc. 4 (1985) 802.
5. HAN HAN-MING, J. World of Chemistry. 4 (1995) 174.