APA (7th ed.) Citation

Library of Congress. (1921). Classification: Class Q, Science. U.S. GPO.

Chicago Style (17th ed.) Citation

Library of Congress. Classification: Class Q, Science. Washington: U.S. GPO, 1921.

MLA (9th ed.) Citation

Library of Congress. Classification: Class Q, Science. U.S. GPO, 1921.

Warning: These citations may not always be 100% accurate.