keeton,. (1980). Biological science (3rd ed.). Norton.
Chicago-čujuhus (17. p.)keeton. Biological Science. 3rd ed. New York: Norton, 1980.
MLA-čujuhus (9. p.)keeton. Biological Science. 3rd ed. Norton, 1980.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.