KaRo -- Distributed Catalog of polish and foreign libraries
possibility of simultaneously searching some library catalogs
NUKat -- National Union Catalog of polish scientific libraries
Library
of Congress
British
Library
Library Hub Discover -
materials held in many UK national, academic and specialist libraries
German libraries - (GBV-VZG)
KVK - Karlsruher Virtueller Katalog
National Library of France
National Library of Russia