Pan American Health Organisation Headquarters Library Catalog.
POPLINE, the world's largest bibliographic database on population, family planning, and related issues, is now available free of charge on the Internet. All 280,000 citations, representing published and unpublished literature, can be accessed for no charge at:http://www.popline.org
PUBLIC LIBRARY OF SCIENCE (PLoS)
A non-profit organization of scientists and physicians committed to making the world's scientific and medical literature a freely available public resource.
PUBMED - NATIONAL LIBRARY OF MEDICINE
A service of the National Library of Medicine, includes over 15 million citations for biomedical articles back to the 1950's. PubMed includes links to many sites providing full text articles and other related resources.