6GL Studio Users Manual [M].U.S.A: Distributed Simulation Technology Inc,2004.
7Vega Prime Programmer's Guide [M]. U.S.A: MultiGen- Paradigm Inc, 2005.
8Milgram,P., Kishino, F.. A Taxonomy of Mixed Reality Visual Displays[J]. 1EICE Transactions on hfformation and Systems, 1994, 77 (12) : 1321-1329.
9Dieterle, E., Clarke, J.. Multi-User Virtual Environments for Teaching and Learning [J]. Encyclopedia of Multimedia Technology and Networking, 2007, (2) : 1033-44.
10Sutherland, I.E.. The Ultimate Display[J]. Multimedia:From Wagner to Virtual Reality, 1965.