Salvador Barrera Hiroki Takahashi Masayuki Nakajima Joyfoot's Cyber System: A Virtual Landscape Walking Interface Device for Virtual Reality Applications. 286-292 2004 conf/cw/2004 CW http://doi.ieeecomputersociety.org/10.1109/CW.2004.43 db/conf/cw/cw2004.html#BarreraTN04