Development of Dialogue Systems for a Mobility Aid for Blind People: Initial Design and Usability Testing. - Thomas Strothotte; Steffi Fritz; Rainer Michel; Andreas Raab; Helen Petrie; Valerie Johnson; Lars Reichert; Axel Schalt (International ACM Conference on Assistive Technologies, 1996)

User-centred design in the development of a navigational aid for blind travellers. - Helen Petrie; Valerie Johnson; Thomas Strothotte; Rainer Michel; Andreas Raab; Lars Reichert (INTERACT, 1997)

The development and testing of evaluation methodologies for wearable computers. - Valerie Johnson (2004)