Alters, S. (1993). Biology today. Mosby.
Lua i Stíl Chicago (17ú heag.)Alters, Sandra. Biology Today. St. Louis: Mosby, 1993.
Lua MLA (9ú heag.)Alters, Sandra. Biology Today. Mosby, 1993.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.