Copac exposes rare and unique research material by bringing together the catalogues of c.90 major UK and Irish libraries. In a single search you can discover the holdings of the UK’s national libraries (including the British Library), many University libraries, and specialist research libraries.

This database of the European Union (EU) contains the complete EU related terminology in all 24 official languages of the EU. -- Diese Datenbank der Europäischen Union (EU) enthält die gesamte EU-bezogene Terminologie in allen 24 EU-Amtssprachen.

The Karlsruhe Virtual Catalogue (KVK) is a meta search engine which allows you to simultaneously access selected library and book trade catalogs worldwide. Altogether, these resources contain hundreds of millions of books, magazines and other media.

A collaborative effort of the Networked Digital Library of Theses and Dissertations (NDLTD), OCLC, VTLS, and Scirus, the NDLTD Union Catalog contains more than one million records of electronic theses and dissertations. For students and researchers, the Union Catalog makes individual collections of NDLTD member institutions and consortia appear as one seamless digital library of electronic theses and dissertations.

Project Gutenberg is a volunteer effort to digitize and archive cultural works. Founded in 1971 by Michael Hart, it is the oldest digital library. Project Gutenberg's mission is "To encourage the creation and distribution of eBooks".