1. Broadcast Satellite Services. http://www.isp-sat.com.
2. GVU's WWW User Surveys. http://www.gvu.gatech.edu/gvu/user_surveys/.
3. INTELSAT. http://www.intelsat.com/products/internet/atint.htm.
4. Skycache. http://www.skycache.com.
5. M. Abrams, C. Stanbridge, G. Abdulla, S. Williams, E. Fox, Caching proxies: limitations and potentials, in: Fourth International World Wide Web Conference, 1995. http://www.w3.org./Conferences/WWW4/.