Library of Congress & Subjet Cataloging Division. (1999). Library of Congress Subject Headings (22nd ed.). The National Bibliographic Service.

Library of Congress and Subjet Cataloging Division. Library of Congress Subject Headings. 22nd ed. Washington: The National Bibliographic Service, 1999.

Library of Congress and Subjet Cataloging Division. Library of Congress Subject Headings. 22nd ed. The National Bibliographic Service, 1999.