| Biblioteques nacionals |
Alemanya. Die
Deutsche Bibliothek  |
| Estats Units. Library
of Congress (LC) |
| França. Bibliothèque
Nationale de France (BNF) |
| Itàlia. Biblioteca
Nazionale Centrale di Firenze |
| Regne Unit. British
Library (BL) |
| Gabriel:
Gateway to Europe's National Libraries |
| Catàlegs col·lectius |
| Agence
Bibliographique de l'Ensegnement Supérieur (ABES)
(Sudoc) |
|
California Digital
Library
(Melvyl) |
| Catalogo
Italiano dei Periodici (ACNP) |
| Catalogue
collectif de France (CCFR) |
| Consortium
of University Research Libraries (CURL)
(COPAC) |
| The
European Library |
| Istituto
Centrale per il Catalogo Unico (ICCU) |
| Karlsruher
Virtueller Katalog (KVK) |
| Opac
of the Union Catalog of Serials (ZDB) |
| Directoris de biblioteques i/o catàlegs |
| Altres
catàlegs, per la Biblioteca de Catalunya |
| Bibliotecas
españolas ... y de todo el mundo, per José Antonio Merlo Vega |
| Die
digitale Bibliothek |
| EUROLIB:
European Community and Associated Institutions Library Co-operation Group
|
| LIBDEX:
The Library index |
| Lib-web-cats
|
| Libweb:
Library Servers via WWW |
| Yahoo.
Libraries |
Catálogo
Colectivo del Patrimonio Bibliográfico Español 
