Citazione Stile APA (7a Edizione)

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

Citazione stile Chigago Style (17a edizione)

Barkley, Andrew, e Paul W. Barkley. Principles of Agricultural Economics. Oxon [England]: Routledge, 2013.

Citatione MLA (9a ed.)

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