1. ZrO2-Lambda-Sonde für die Gemischregelung im Kraftfahrzeug;Wiedenmann,1995
2. K.H. Friese, H.M. Wiedenmann, F. Stanglmeier, Electrochemical sensor to determine the oxygen concentration in gas mixtures, International Patent Specification WO 95/25276, 1995.
3. K.H. Friese, H.M. Wiedenmann, Sensor for determining the oxygen content of gas mixtures, European Patent Specification EP0748443, 1995.
4. T. Yamada, Oxygen sensor, US Patent Specification US 4505807, (1982).
5. W.J. Kaiser, E.M. Logothetis, Exhaust gas oxygen sensors based on TiO2, SAE Paper 830167, 1983.