Citazione Stile APA (7a Edizione)

Ward, J. A., & Hetzel, H. R. (1980). Biology: Today and tomorrow. Minn West.

Citazione stile Chigago Style (17a edizione)

Ward, Jack A., e Howard R. Hetzel. Biology: Today and Tomorrow. St. Paul.: Minn West, 1980.

Citatione MLA (9a ed.)

Ward, Jack A., e Howard R. Hetzel. Biology: Today and Tomorrow. Minn West, 1980.