APA ציטוט

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

Trích dẫn kiểu Chicago

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

ציטוט MLA

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