- DARE : Database of Abstracts of Reviews of Effects

Database of evidence-based systematic reviews of diagnostic tests, public health, pharmacology, surgery, psychology and the health care system.
- Dictionary of Literary Biography

Biographical and critical information on influential literary personalities from all geographical areas, periods and genres.
- Dictionary of National Biography (Oxford)

Lives of over 55,000 people who have shaped the British past.
- Directory of Open Access Journals : DOAJ

Locate open access journals, defined as journals using a funding model that does not charge readers or their institutions for access. Journals must exercise peer-review or editorial quality control to be included in the Directory.
- Directory of UK Map Collections

List of map collections in the U.K. Produced by the British Cartographic Society.
- DIRLINE : Directory of Health Organizations

Lists organizations willing to respond to public inquiries in their specialty areas, including toxicology, occupational health, and more.
- Dissertations & Theses

Provides downloadable doctoral dissertations originating from universities in the Big Ten conference from 1997 to present. More dissertations from other North American and European universities are available for preview and individual purchase.
- DynaMed

Evidence-based reference tool intended for physicians and other health care professionals for use primarily at the point-of-care.