Freeman, S. (2011). Biological science (Fourth edition.). Benjamin Cummings.
Cita Chicago (17th ed.)Freeman, Scott. Biological Science. Fourth edition. Boston: Benjamin Cummings, 2011.
Cita MLA (9th ed.)Freeman, Scott. Biological Science. Fourth edition. Benjamin Cummings, 2011.
Atenció: Aquestes cites poden no estar 100% correctes.