Coverage: 1969–present. A bibliographic database providing abstracts and indexing to the world's scientific and technical literature.
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Provides access to journals published by the American Institute of Physics and their publishing partners.
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Coverage: 1893–present. The online archive for the Physical Review, published by the American Physical Society.
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arXiv is a pre-print service in the fields of physics, mathematics, non-linear science, computer science, and quantitative biology. That is, the works are not yet fully vetted, edited, or published. Use information herein accordingly.

Multidisciplinary subject index. Covers millions of research publications connected by more than 1.6 billion citations. A user account is required, free to make and use.

Coverage: 1989–present. Access to Science Citation Index, Social Science Citation Index, and/or Arts & Humanities Citation Index. This resource has broad, multidisciplinary coverage of scholarly articles. A feature that is somewhat unique to this resource is citation searching; using an important historic reference one can see the more recent articles that cited the key reference. Part of Web of Knowledge.
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Coverage: 1999–present. Offers more than a quarter of the world's scientific, medical, and technical information online. Full text is only available for a limited number of the titles.

Multidisciplinary. Use Google Search Operators to focus retrieval results.