Osborn, F. (1953). The limits of the earth. Little, Brown.
Lua i Stíl Chicago (17ú heag.)Osborn, Fairfield. The Limits of the Earth. Boston: Little, Brown, 1953.
Lua MLA (9ú heag.)Osborn, Fairfield. The Limits of the Earth. Little, Brown, 1953.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.