Cita APA

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

Citación estilo Chicago

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

Cita MLA

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