APA (7th ed.) Citation

Library of Congress. Office for Subject Cataloging Policy. (1990). LC classification outline (6th ed.). The Office.

Chicago Style (17th ed.) Citation

Library of Congress. Office for Subject Cataloging Policy. LC Classification Outline. 6th ed. Washington: The Office, 1990.

MLA (9th ed.) Citation

Library of Congress. Office for Subject Cataloging Policy. LC Classification Outline. 6th ed. The Office, 1990.