1. Clark JH. Hierarchical geometric models for visible surface algorithms. Communications of the ACM 1976;19(10):547?554
2. Carey R, Bell G. The Annotated VRML 2.0 Reference Manual Addison-Wesley Reading, Mass
3. Chrislip CA, Ehlert Jr JF. Level of detail models for dismounted infantry in NPSNET-IV.8.1. Master's thesis, Naval Postgraduate School, Monterey, Calif. 1995
4. Vince J. Virtual reality techniques in flight simulation. In Virtual reality systems. Farnshaw RA, Gigante MA, Jones H eds. London: Academic Press, 1993
5. Kemeny A. A cooperative driving simulator. Proceedings of the International Training Equipment Conference (ITEC) 1993;67?71