APA (7th ed.) Citation

Hansen, P. S. (1971). An introduction to twentieth century music. Allyn and Bacon.

Chicago Style (17th ed.) Citation

Hansen, Peter S. An Introduction to Twentieth Century Music. Boston: Allyn and Bacon, 1971.

MLA (9th ed.) Citation

Hansen, Peter S. An Introduction to Twentieth Century Music. Allyn and Bacon, 1971.