Freeman, S. (2011). Biological science (Fourth edition.). Benjamin Cummings.
Chicago-čujuhus (17. p.)Freeman, Scott. Biological Science. Fourth edition. Boston: Benjamin Cummings, 2011.
MLA-čujuhus (9. p.)Freeman, Scott. Biological Science. Fourth edition. Benjamin Cummings, 2011.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.