Article Sciences: Scientific article search and order engine, a service provided by Institut de l'Information Scientifique et Technique (INIST) of Centre National de la Recherche Scientifique (CNRS), France.
Entrez: Simultaneously search multiple life sciences databases at the National Center for Biotechnology Information (NCBI).
Gateway: The National Library of Medicine Gateway allows users to search in multiple retrieval systems at the U.S. National Library of Medicine.
MedHunt: A tool from Health on the Net that searches the full text of 60,000 medical documents. Searches can be narrowed by location or type of source.
Medic8.com: Directory and medical search engine for healthcare professionals.
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.