Cita APA (7a ed.)

Library of Congress. (1920). Classification: Class H Social sciences (2nd ed.). Library of Congress.

Cita Chicago Style (17a ed.)

Library of Congress. Classification: Class H Social Sciences. 2nd ed. Washington: Library of Congress, 1920.

Cita MLA (9a ed.)

Library of Congress. Classification: Class H Social Sciences. 2nd ed. Library of Congress, 1920.