HEIDI

Catalogue for libraries of Heidelberg University

In addition:

DigiKat

Digitized Alphabetical Card Catalogue for holdings of Heidelberg University Library published until 1961.

Peace Palace Library

Catalogue of the Peace Palace Library, Den Haag

British Library

Library of Congress Online Catalog

Contains 17 million catalog records for books, serials, manuscripts, maps, music, recordings, images, and electronic resources in the Library of Congress collections.

Harvard Library (HOLLIS+)