References
[Selberg and Etzioni, 1995]
Selberg, Erik and Etzioni, Oren. Multi-engine search and comparison using the MetaCrawler; 1995. <URL:http://metacrawler.cs.washington.edu:8080/paper-www4/metacrawler.html>.
Cyberspace geography visualization - 15 October 1995
Luc Girardin, The Graduate Institute of International Studies