PubMed, provided by the National Library of Medicine, contains over 33 million citations covering the fields of medicine, nursing, dentistry, veterinary medicine, the health care system, and the preclinical sciences.

This list is limited to journals published online with the assistance of HighWire Press. Currrently, there are over 2,117,523 free full-text articles available. There are 13 journals with free trial periods, 49 that are completely free, 282 that offer free back issues, and 1271 that are only available for pay per view

The research articles in all journals published by BioMed Central are Open Access. They are immediately and permanently available online without charge. A number of journals require an institutional or a personal subscription to view other content, such as reviews or paper reports. Free trial subscriptions to these journals are available

Free, full text, quality controlled scientific and scholarly journals, covering all subjects and many languages

PLoS publishes seven peer-reviewed open-access journals. The journals vary in their selectivity and contain differing amounts of commentary articles from opinion leaders in a variety of scientific disciplines.The journals are editorially independent

NCBI Bookshelf provides free access to books and government documents in the life sciences and healthcare