Open access to 546,172 e-prints in Physics, Mathematics, Computer Science, Quantitative Biology, Quantitative Finance and Statistics
ADS contains abstracts and citations for materials in astronomy and astrophysics, instrumentation, physics and geophysics, Los Alamos preprints, and many archives.
Multidisciplinary index to scholarly and authoritative articles. Provides access to all three parts of the Citation Index: Arts and Humanities, Social Science and Science. Search by subject, author, journal title. Cited Reference Search finds articles that cite an author or article that you specify.