Weidong Geng Wolfgang Strauss Monika Fleischmann Vladimir Elistratov Marina Kolesnik Perceptual User Interface in Virtual Shopping Environment. 365-378 2003 3 Int. J. Image Graphics 2 http://dx.doi.org/10.1142/S0219467803001056 db/journals/ijig/ijig3.html#GengSFEK03