Ioannis Giannopoulos Ourania Hatzi Mara Nikolaidou Dimosthenis Anagnostopoulos Realistic virtual environments navigable over the www. 30 2007 SCSC http://doi.acm.org/10.1145/1357910.1358137 conf/scsc/2007 db/conf/scsc/scsc2007.html#GiannopoulosHNA07