APA (7. basım) Alıntı

Harland, W. B., & Armstrong, R. L. (1990). A geologic time scale 1989. Cambridge University Press.

Chicago Style (17. basım) Atıf

Harland, W. Brian, ve Richard L. Armstrong. A Geologic Time Scale 1989. Cambridge: Cambridge University Press, 1990.

MLA (9th ed.) Atıf

Harland, W. Brian, ve Richard L. Armstrong. A Geologic Time Scale 1989. Cambridge University Press, 1990.