Hit Link - Hit Sites - Reference Category http://www.hitlink.org/ Last Hit Links - Reference Category en-us HitLink Bot 2.0 Reference <![CDATA[Ref Desk]]>Refdesk is a free and family friendly web site that indexes and reviews quality, credible, and current web-based reference resources. ]]><![CDATA[Reference]]>Reference.com - a free online encyclopedia and information reference. Research articles from Columbia Encyclopedia and Encyclopedia Britannica. ]]>