Walking with and Without Walking: Perception of Distance in Large-Scale Urban Areas in Reality and in Virtual Reality. - Michael M. Popp; Edna Platzer; Matthias Eichner; Marion Schade (Presence Teleoperators Virtual Environ., 2004)

Spatial cognition research: the human navigation process and its comparability in complex real and virtual environments. - Edna Platzer (dissertation.de, 2005)