1. AltaVista: http://www.altavista.com/
2. AskJeeves: http://www.ask.com/
3. Direct Hit: The Direct Hit Technology — A White Paper, Direct Hit Inc., http://system.directhit.com/whitepaper.html
4. Google: http://www.google.com/
5. Javascript: Javascript Reference, Netscape, http://developer.netscape.com/docs/manuals/communicator/jsref/contents.htm