Academic Search Complete
Provides references to articles from scholarly journals and magazines. Full text is available for many articles.
General Science Abstracts (1984-)
Provides references to articles from scientific journals in physics.
Google Scholar
Provides references to scholarly books and articles.
OCLC Electronic Collections Online (1995-)
Provides references to articles from academic journals.
SpringerLink
Lists articles in SpringerLink science journals. Includes some coverage of physics. Full text is available for most articles.
WorldCat
Provides references to books, videos, cds and other items in academic and public libraries.