APA-referens (7:e uppl.)

Fels, R. (1966). An introduction to economics: The challenge to the American economy (2nd ed.). Allyn and Bacon.

Chicago-referens (17:e uppl.)

Fels, Rendings. An Introduction to Economics: The Challenge to the American Economy. 2nd ed. Boston: Allyn and Bacon, 1966.

MLA-referens (9:e uppl.)

Fels, Rendings. An Introduction to Economics: The Challenge to the American Economy. 2nd ed. Allyn and Bacon, 1966.