Catalogue Collectif de France

Catalogue Collectif de France
(French Union Catalogue)

The Catalogue Collectif de France (French Union Catalogue) has an extraordinarily rich collection of early journals, particularly those published in the French language.
Its cataloguing data is generally of very high quality, usually containing detailed continuation notes that allow one to track the history of name changes of the journals in its collections.
The following web-interface to their catalogue is well designed:

Choose LOCALISATION DES DOCUMENTS in order to do a search over the catalogues of the 160 library (including that of the Bibliothèque Nationale de France) participating in the Catalogue Collectif de France.