1. Karl Kordesch and Gunter Simader, Fuel Cells and Their Applications, Weinheim, New York, 1996.
2. D.A. Landsman, F.S. Luszak, US Patent 4,186,110, 1984.
3. C.Z. Wan, Eur. Pat. 129,399 AI, 1984.
4. F.S. Luszak, D.A. Landsman, US Patent 4,447,506, 1984.
5. T. Itoh, K. Katoh, Jpn. Pat. Appl. 211,621, 1988.