Standard index to statistics literature, indexes over 2000 journals.MathSciNet
American Mathematical Society database of abstracts of mathematics literature. Over 2.5 million brief authoritative reviews of mathematics papers and books from 1940 to present.Zentralblatt MATH
European database of abstracts of mathematical literature. Over 3 million brief authoritative reviews of mathematics papers and books from 1868 to present.
Mathematics interface for the arXiv, a freely available digital library of over 750,000 preprint papers in physics, mathematics, quantitative biology, quantitative finance, and statistics.