APA aipamena

Richard W Ojakangas. (1976). The earth: Past and present. New York: McGraw-Hill.

Chicago Style aipamena

Richard W Ojakangas. The Earth: Past and Present. New York: McGraw-Hill, 1976.

MLA aipamena

Richard W Ojakangas. The Earth: Past and Present. New York: McGraw-Hill, 1976.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.