एपीए उद्धरण

Harland, W. B. (1982). Geologic time scale. Cambridge University Press.

शिकागो स्टाइल उद्धरण

Harland, W B. Geologic Time Scale. London: Cambridge University Press, 1982.

एमएलए उद्धरण

Harland, W B. Geologic Time Scale. Cambridge University Press, 1982.