Cita APA

Ward, J. A., & Hetzel, H. R. (1980). Biology today and tomorrow. West publishing co.

Chicago Edition Citation

Ward, Jack A., i Howard. R. Hetzel. Biology Today and Tomorrow. New York: West publishing co, 1980.

Cita MLA

Ward, Jack A., i Howard. R. Hetzel. Biology Today and Tomorrow. West publishing co, 1980.