Cita APA (7th ed.)
Willoughby, D. (1990). The world of music. WM.C.Brown Pub.
Cita Chicago (17th ed.)
Willoughby, David. The World of Music. U. S. A.: WM.C.Brown Pub, 1990.
Cita MLA (9th ed.)
Willoughby, David. The World of Music. WM.C.Brown Pub, 1990.
Atenció: Aquestes cites poden no estar 100% correctes.