Darwin, C. (1998). The origin of species. Wadsworth.
Lua i Stíl Chicago (17ú heag.)Darwin, Charles. The Origin of Species. Hertfordshire: Wadsworth, 1998.
Lua MLA (8ú heag.)Darwin, Charles. The Origin of Species. Wadsworth, 1998.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.