The Astrophysics Data System (ADS) is a digital library portal for researchers in astronomy and physics, operated by the Smithsonian Astrophysical Observatory (SAO) under a NASA grant.
The ADS maintains three bibliographic collections containing more than 15 million records covering publications in astronomy and astrophysics, physics, and general science, including all arXiv e-prints. Abstracts and full-text of major astronomy and physics publications are indexed and searchable and browsable.
Consists of physics journals from The American Institute of Physics (AIP) and its member societies including the American Vacuum Society, the Acoustical Society of America, and the American Association of Physics Teachers.
Provides physics research journals, including Physical Review Letters, Reviews of Modern Physics, and the Physical Review series. The Physical Review Online Archive provides access to articles in these journals all the way back to the founding of The Physical Review in 1893.
Scopus is an abstract and citation database of peer-reviewed literature covering scientific journals, books, conference proceedings, datasets, and funding data dating back to 1970. Delivering a comprehensive overview of the world’s research output in the fields of science, technology, medicine social sciences and arts, and humanities. Scopus features tools to track, analyze and visualize research.
The Scopus Information site contains a wealth of resources including:
• User guides and tips
• Title lists
• Quick tips and Frequently Asked Questions
INSPIRE provides author disambiguation for profiles and search; detailed record pages; searchable arXiv text; figure/captions searching; LHC experimental notes; and excellent content. Its front page includes a long list of search operators so you can get granular from the get-go. It predominantly serves high-energy physics, with some coverage of overlap areas.