1. Anonym:Transistorized amplifier to the pointer meter. Radio and TV-News 2: 43, 1958.
2. Anonym:Elektronisches Voltmeter. Elektronik 11: 196, 1962.
3. Blondfield, E. F., Barter, L., Watanabe, H.:New designs in oxygen amplifiers for Clark type sensors. Beckman Instr. publ. 13 TW-196 Pittsburgh Conference, 1963.
4. Brehmer, Ch., Le Petit, G.:Ein Gerät zur elektrochemischen Sauerstoffmessung in der Blutbahn. Acta Biol. Med. Ger. 11: 447, 1963.
5. Carilli, A., Chain, E. B., Gualandi, G., Morisi, G.:Continuous measurement of dissolved oxygen during fermentation in large fermenters. Sci. Rep Ist-Super. di Sanita 1: 177, 1961.