1. G. Grüneberg, W. Wicke, E. Justi, British Patent 994448 (1961), French Patent FR 1321373.
2. G. Goebel, B.D. Struck, W. Vielstich, in: W. Vielstich (Ed.), Fuel Cells—Modern Processes for the Electrochemical Production of Energy (English translation by G.J.G. Ives), Wiley/Interscience, NY, 1965, pp. 374–376.
3. Proceedings of the 1st International Meeting on Chemical Sensors;Miura,1983