APA
Library of Congress, . (2011). Anual Report of the Librarian of Congress. Washington D. C: .
Chicago
Library of Congress, . 2011. Anual Report of the Librarian of Congress. Washington D. C: .
Harvard
Library of Congress, . (2011). Anual Report of the Librarian of Congress. Washington D. C: .
MLA
Library of Congress, . Anual Report of the Librarian of Congress. Washington D. C: . 2011.
