APA-referens (7:e uppl.)

Barkley, A., & Barkley, P. W. (2013). Principles of agricultural economics. Routledge.

Chicago-referens (17:e uppl.)

Barkley, Andrew, och Paul W. Barkley. Principles of Agricultural Economics. London, New York: Routledge, 2013.

MLA-referens (9:e uppl.)

Barkley, Andrew, och Paul W. Barkley. Principles of Agricultural Economics. Routledge, 2013.