APA (7e ed.) Bronvermelding

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

Chicago (17e ed.) Bronvermelding

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

MLA (9e ed.) Bronvermelding

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