MathSciNet provides coverage of the international research literature in mathematics as well as mathematically-related research in computer science, statistics, econometrics, and other disciplines. MathSciNet includes reviews from journal articles, books, conference proceedings, and proceedings papers. The database also includes reviews from Current Mathematical Publications which are updated daily.
ArXiv.org is an open-access electronic repository of over 500,000 electronic scholarly articles. It is an important database in physics and math but also covers computer science and quantitative biology.
Current and retrospective multidisciplinary information from approximately 8,700 of the most prestigious, high impact research journals in the world. Use Web of Science to perform a cited reference search, where you can look up an article and see how many times it has been cited.
The Web of Science Core Collection includes the following databases:
Science Citation Index (1900-present)
Social Sciences Citation Index (1900-present)
Arts & Humanities Citation Index (1975-present)
Conference Proceedings Citation Index (1975-present)
Book Citation Index (2005-present)
Emerging Sources Citation Index (2015-present)
Current Chemical Reactions (1985-present)
Index Chemicus (1993-present)