Krogh, D. (2002). Biology: A guide to the natural world (2nd ed.). Prentice Hall.
Lua i Stíl Chicago (17ú heag.)Krogh, David. Biology: A Guide to the Natural World. 2nd ed. Upper Saddle Riever, New Jersey: Prentice Hall, 2002.
Lua MLA (9ú heag.)Krogh, David. Biology: A Guide to the Natural World. 2nd ed. Prentice Hall, 2002.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.