1. M. E. Royer, C. R. Acad. Sci. 70 (1870) 731.
2. J.-P. Randin, in Encyclopedia of Electrochemistry of the Elements, Vol. VII, Ed. by A. J. Bard, Marcel Dekker, New York, 1976, Chap. 1.
3. J. R. Bolton and D. O. Hall, Annu. Rev. Energ. 4 (1979) 353.
4. M. Halmann, in Energy Resources through Photochemistry and Catalysis, Ed. by M. Gratzel, Academic, New York, 1983, Chap. 15.
5. D. Root and E. Attanasi, Am. Assoc. Petrol. Geol. Bull (1978).