Purves/Orians. (1987). The Science Of Biology. Sinauer Association Inc.
Lua i Stíl Chicago (17ú heag.)Purves/Orians. The Science Of Biology. Sinauer Association Inc, 1987.
Lua MLA (8ú heag.)Purves/Orians. The Science Of Biology. Sinauer Association Inc, 1987.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.