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.