Curtis, F. D., & Urban, J. (1949). Biology in daily life. Ginn.
Lua i Stíl Chicago (17ú heag.)Curtis, Francis D., agus John Urban. Biology in Daily Life. Boston: Ginn, 1949.
Lua MLA (8ú heag.)Curtis, Francis D., agus John Urban. Biology in Daily Life. Ginn, 1949.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.