1990: Einfluß der Oberfläche auf die Elektrooptische Kennlinie in nematischen Flüssigkristallzellen
1991: Threshold Behaviour and Electrooptical Properties of Twisted Nematic Layers with Weak Anchoring in the Tilt and Twisted Angle
1991: Threshold behavior and electrooptical properties of twisted nematic layers with weak anchoring in the tilt and twist angle