Lua APA (7ú heag.)

Harland, W. B. (1989). A geologic time scale 1989. Cambridge University Press.

Lua i Stíl Chicago (17ú heag.)

Harland, Walter Brian. A Geologic Time Scale 1989. New York: Cambridge University Press, 1989.

Lua MLA (9ú heag.)

Harland, Walter Brian. A Geologic Time Scale 1989. Cambridge University Press, 1989.

Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.