1. Soda News, Japan Soda Industry Association, No. 4 (1981).
2. K. Hass, Chem. Ing. Techn. 47, 121 (1975).
3. Annual Report of the Electrolytic Industries, Electrochemical Society, 1970–1979.
4. Data published by Japan Soda Industry Association.
5. R. S. Karpiuk and S. D. Argade, J. Electrochem. Soc. 122, 310C (1975).