APA
Library of Congress Catologing, Library of Congress Catologing, . (1939). The opera libretto library. New York, Estados Unidos de América: Avenel Book.
Chicago
Library of Congress Catologing, Library of Congress Catologing, . 1939. The opera libretto library. New York, Estados Unidos de América: Avenel Book.
Harvard
Library of Congress Catologing, Library of Congress Catologing, . (1939). The opera libretto library. New York, Estados Unidos de América: Avenel Book.
MLA
Library of Congress Catologing, Library of Congress Catologing, . The opera libretto library. New York, Estados Unidos de América: Avenel Book. 1939.
