Below are a series of links to different Spanish and foreign libraries, which may be of interest to you when you need to locate a document that the library does not have.

Spanish library catalogues

Library
	National Library of Spain
	State Public Libraries
	Collective Catalogue of Spanish Bibliographic Heritage
	CSIC Bibliographic Catalogue
	Castilla y León Libraries
	Collective Catalogue of the Universities of CataloniaCollective Catalogue of Cataluña

Foreign library catalogues

Country	Icon	Libraries
Germany		Karlsruher Virtueller Katalog KVK
United Kingdom		The British Library. Londres Library Hub Discover (formerly COPAC, Collective Catalogue of UK University and Research Libraries)
United States of America		Library of Congress. Washington National Union Catalog of Manuscript Collections (NUCMC) U.S. National Library of Medicine New York Public Library Yale University Library
France		Bibliothèque nationale de France. París Union catalogue of France SUDOC: university documentation system