PubMed is a web interface that allows you to search MEDLINE, the National Library of Medicine's premier database of citations and abstracts for biomedical research articles. The core subject is medicine, but subject coverage also includes bioethics, biology, chemistry, dentistry, environmental health, genetics, gerontology, health care planning and administration, history of medicine, hospital administration, microbiology, nutrition, nursing (International Nursing Index), physiology, pre-clinical sciences, public health, sports medicine, veterinary medicine and zoology. MEDLINE covers over 4,800 journals published in the United States and 70 other countries. The database contains over 15 million citations dating back to 1950. Coverage is worldwide and updated weekly. Learn more about PubMed at: https://pubmed.ncbi.nlm.nih.gov/about/. or Try the Tutorial at: http://www.nlm.nih.gov/bsd/pubmed_tutorial/m1001.html

Web of Science provides access to: the Science Citation Index Expanded 1900-present; the Social Sciences Citation Index 1956-present; and the Arts & Humanities Citation Index 1975-present. Web of Science indexes articles from thousands of journals and also indexes the citations used in those articles, thus allowing the user to see which papers have cited a core paper, and how many times a paper was cited in a given time period. Covers published content is almost every discipline.

Compendex is the most comprehensive interdisciplinary engineering database in the world with over 9 million records referencing 5,000 engineering journals and conference materials dating from 1884.