- OPAC SBN Servizio Bibliotecario Nazionale: Catalogue of the National Library Service (SBN) that is the main Italian libraries network.
- ACNP Catalogo italiano dei periodici: Italian catalogue of serials; to search both the printed and online journals owned by the Italian libraries.
- MAI - Metaopac Azalai Italiano: Simultaneous query through all the Italian library catalogues available online. Use this Opac to search unusual or rare document.
- KVK - Karlsruhe Virtual Catalog: Meta search interface for books and serials in library and book trade catalogs worldwide.
- WorldCat: Catalogue of the world's largest network of libraries (OCLC).