2. Search engines specialized in medicine and biology

PubMed , www.ncbi.nlm.nih.gov/pubmed , is the free web interface to the Medline database launched in 1996:

• over 22 million article references (and online books);

• multiple search and monitoring functionalities: expert search, refinement, export to bibliographic managers, RSS feeds for queries, related searches, linked image searches...

Alternative interfaces have been developed:

• GoPubMed (semantic interface with clustering) ;

• PubGet (interface for immediate...