2[1] Burnside C D. Mapping from Aerial Photographs [M]. G. Britain: Granada Publishing Limited, 1979. 248-258.
3[2] Church E. Revised geometry of the aerial photograph [R]. Bulletins on Aerial Photogrammetry, No.15, Syracuse University, 1945.
4[3] Hoxie S, et al. Developments in standards for networked virtual reality [J]. IEEE Computer Graphics and Applications, 1998 March-April, 182: 6-9.
5[4] Calvin J, et al. The SIMNET virtual world architecture [A]. Proceedings of the IEEE Virtual Reality Annual International Symposium 1998 [C]. 450-455.
6[5] Carlsson C, Hagsand O. DIVE-A multi-user virtual reality system [A]. Proceedings of the IEEE Virtual Reality Annual International Symposium(VRAIS'93) [C].394-400.
7[6] Singh G, Serra L, Png W&Ng H. A software toolkit for networked virtual worlds [Z]. Presence, (1994). Bricknet:3(1)19-34.
