UB Libraries Catalog
For EU material: Search the UB Libraries Catalog; try limiting the publisher to European Union or adding to a keyword search the phrase “European Communities” (for older materials) or “European Union”. There is no one location for European Union items; they are scattered throughout the collection by appropriate Library of Congress call numbers.

WorldCat
A mega-library catalog containing more than 200 million records contributed by 25,000 libraries around the world.

Europa
EUROPA is the official EU website that provides access to information published by all EU institutions, agencies and bodies.

European Union Publications Office
Its task is to publish the publications of the institutions of the European Union.  Also provides a link to the EU Bookshop https://bookshop.europa.eu/en/home/ .

European Commission Library (EC Library)
Lists the complete holdings of the EU Central Library since 1978.  ECLAS focuses on publications of the European Union and has also an extensive collection of publications of international organisations such as the UN, OECD, World Bank, etc.  The catalogue contains a wealth of books and journals from commercial publishers in all EU languages

The European Library
An online portal which offers quick and easy access to the collections of the 48 National Libraries of Europe and leading European Research Libraries.

JISC Discovery Hub
Search over 80 UK and Irish academic, national & specialist library catalogs.

France: Union Catalog of France

Germany: Union Catalog of Germany