Cita APA (7th ed.)

Ewen, D. (1955). Encyclopedia of the opera. A.A. Wyn.

Cita Chicago (17th ed.)

Ewen, David. Encyclopedia of the Opera. New York: A.A. Wyn, 1955.

Cita MLA (9th ed.)

Ewen, David. Encyclopedia of the Opera. A.A. Wyn, 1955.