The SOA/NASA Astrophysics Data System (ADS) is a digital library portal for researchers in astronomy and physics operated by the Smithsonian Atrophysical Observatory (SAO). It maintains three databases which cover publications in astronomy and astrophysics, physics, and the arXiv e-prints.
Physical Review Online Archive, or PROLA provides access to the following: Physical Review Series I and II (1893-1969), Physical Review A - D (1970-2016), Physical Review E (1993-2016), Physical Review Letters (1958-2016), and Reviews of Modern Physics (1929-2016).
At the end of each calendar year, PROLA adds another year of content.
Web of Science (WoS) indexes leading scholarly journals, books, proceedings, and other formats. Its major subject areas include the natural and social sciences and arts and humanities with coverage back to 1900. The heart of WoS is the Web of Science Core Collection, which indexes thousands of scholarly journals by author, author affiliation, and cited reference. In addition to the Core Collection, Web of Science provides access to several regional, subject, and format-specific database.
The suite of video tutorials teach aspects of searching, analyzing results, creating a researcher profile, and more. EndNote Web, the bibliographic management tool, is integrated into WoS.