Danielson, E. W. (1989). Earth science. Collier Macmillan.
Chicago Style aipamenaDanielson, Eric W. Earth Science. New York: Collier Macmillan, 1989.
MLA aipamenaDanielson, Eric W. Earth Science. Collier Macmillan, 1989.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.