Library of Congress Authorities
http://authorities.loc.gov/webvoy.htm

Using Library of Congress Authorities, you can search, browse and view authority headings for Subject, Name, Title and Name/Title combinations; and download authority records in MARC format for use in a local library system. This service is offered free of charge. This has been added to the tools section of Research Resources Subject Tracer™ Information Blog. This has been added to Business Intelligence Resources Subject Tracer™ Information Blog. This will be added to Academic and Scholar Search Engines and Sources white paper.