APA (7th ed.) Citation

Library of Congress. Research Services. (1929). L.C. classification, additions and changes. Various.

Chicago Style (17th ed.) Citation

Library of Congress. Research Services. L.C. Classification, Additions and Changes. [Washington]: Various, 1929.

MLA (9th ed.) Citation

Library of Congress. Research Services. L.C. Classification, Additions and Changes. Various, 1929.