RITCHIE, D. A. (1983). Biology / Donald D. Ritchie. Addison Wesley.
Lua i Stíl Chicago (17ú heag.)RITCHIE, Donald A. Biology / Donald D. Ritchie. Addison Wesley, 1983.
Lua MLA (8ú heag.)RITCHIE, Donald A. Biology / Donald D. Ritchie. Addison Wesley, 1983.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.