Usually, we use library online catalogs in order to find books and scores.
The Indiana University online catalog.
IUCAT, Indiana University's online library catalog, provides comprehensive access to millions of items held by the IU Libraries statewide, including books, recordings, US government publications, periodicals, and other types of material. Users can access IUCAT from any Internet-connected computer or device, whether in the libraries, on campus, or off campus.
Thousands of libraries may be searched from this one catalog; Interlibrary Loan requests can also be made.
WorldCat is OCLC's Online Union Catalog. It is the world's most comprehensive bibliography, with more than 33 million bibliographic records from libraries around the world. Use WorldCat to do a comprehensive search of published material, to verify citations, or to identify other libraries that own an item.