McCombs, D. (2000). Ultima thule. Yale University Press.
Lua i Stíl Chicago (17ú heag.)McCombs, Davis. Ultima Thule. New Haven: Yale University Press, 2000.
Lua MLA (9ú heag.)McCombs, Davis. Ultima Thule. Yale University Press, 2000.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.