o connect users to primary research content, by enabling publishers to work collectively. CrossRef is also the official DOI® link registration agency for scholarly and professional publications.
Es gibt eine Menge grüne Suchmaschinen, oder solchen, die einem wohltätigen Zweck dienen. Diese Seiten sind sehr ähnlich zu Google oder Yahoo und basieren auch in vielen Fällen auch auf deren Suchtechnologie. Anders jedoch als ihre großen Brüder verwenden sie ihre Werbeeinnahmen für wohltätige Zwecke.
The Internet Archive is a 501(c)(3) non-profit that was founded to build an Internet library, with the purpose of offering permanent access for researchers, historians, and scholars to historical collections that exist in digital format. Founded in 1996 and located in the Presidio of San Francisco, the Archive has been receiving data donations from Alexa Internet and others. In late 1999, the organization started to grow to include more well-rounded collections. Now the Internet Archive includes texts, audio, moving images, and software as well as archived web pages in our collections.
ChemSpider is a free access service providing a structure centric community for chemists. Providing access to millions of chemical structures and integration to a multitude of other online services ChemSpider is the richest single source of structure-base
You can use words or symbols called search operators to filter your Gmail search results. You can also combine operators to filter your results even more.
How to use a search operator Go to