Entrez Simultaneously search multiple life sciences databases at the National Center for Biotechnology Information (NCBI).
http://www.ncbi.nlm.nih.gov/gquery/gquery.fcgi - [ Report Dead Link ]
Gateway The National Library of Medicine Gateway allows users to search in multiple retrieval systems at the U.S. National Library of Medicine.
http://gateway.nlm.nih.gov/ - [ Report Dead Link ]
Healia Personalized consumer health search engine. Using specialized algorithms, it attempts to evaluate the quality of health-related content found on web pages.
http://www.healia.com/ - [ Report Dead Link ]
Medical World Search This tool has the ability to query other search engines, also provides a discussion forum, medical spelling and drug acronym devices. All users must register and pay annual membership fee.
http://www.mwsearch.com/ - [ Report Dead Link ]