1. Nielsen/NetRatings IncInternet usage statistics for the month of December 2001 (United Kingdom)2002 Jan 24http://epm.netratings.com/uk/web/NRpublicreports.usagemonthly
2. Nua Internet SurveysHow many online?200182002 Jan 24http://www.nua.com/surveys/how_many_online/index.html
3. Google offers immediate access to 3 billion Web documents [press release]200112112002 Feb 15Mountain View, CalifGoogle Inchttp://www.google.com/press/pressrel/3billion.html
4. TaylorHThe Harris Poll #19: Cyberchondriacs Update20014182002 Feb 15http://www.harrisinteractive.com/harris_poll/index.asp?PID=229