Frank Steinicke Gerd Bruder Klaus Hinrichs Markus Lappe Brian Ries Victoria Interrante Transitional environments enhance distance perception in immersive virtual reality systems. 19-26 2009 APGV http://doi.acm.org/10.1145/1620993.1620998 conf/apgv/2009 db/conf/apgv/apgv2009.html#SteinickeBHLRI09