Standard index to statistics literature, indexes over 2000 journals.
MathSciNetAmerican 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 MATHEuropean database of abstracts of mathematical literature. Over 3 million brief authoritative reviews of mathematics papers and books from 1868 to present.
Mathematics Front for the arXiv
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.

