Kraus, D., & Perkins, O. E. (1974). Concepts in modern biology. Cambridge Book.
Lua i Stíl Chicago (17ú heag.)Kraus, David, agus Otho E. Perkins. Concepts in Modern Biology. New York: Cambridge Book, 1974.
Lua MLA (9ú heag.)Kraus, David, agus Otho E. Perkins. Concepts in Modern Biology. Cambridge Book, 1974.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.