Online version of Mathematical Reviews and Current Mathematical Publications produced by the American Mathematical Society. Contents: evidence and reviews of mathematical research literature from 1940 onwards.
Online version of the Zentralblatt MATH (zbMATH) and related matters, published amongst others by the European Mathematical Society. Contents: evidence and reviews of mathematical research literature since 1931. Since September 2006, it has included the “Jahrbuch über die Fortschritte der Mathematik“ with evidence and reviews of mathematical research literature from 1868 to 1931 and links to around 13 000 digitised full texts. Open Access since 1.1.2021.
Nazi rule in the 1930s made it impossible to publish freely in the German Zentralblatt. This prompted the American Mathematical Society to found its own journal, Mathematical Reviews, in 1940. To date, both publications exist side by side, even though MathSciNet and MATH are internationally oriented and therefore overlap. However, the reviews of the same articles are different.
Further reading on the history of Mathematical Reviews.