APA-viite (7. p.)

Powers, L. E., & McSorley, R. (2000). Ecological principles of agriculture. Delmar.

Chicago-viite (17. p.)

Powers, Laura E., ja Robert McSorley. Ecological Principles of Agriculture. Africa: Delmar, 2000.

MLA-viite (9. p.)

Powers, Laura E., ja Robert McSorley. Ecological Principles of Agriculture. Delmar, 2000.