Cita APA (7a ed.)

OJAKANGAS, R. W. (1976). The earth, past and present - Richard W. Ojakangas, David G. Darby. McGraw-Hill.

Cita Chicago Style (17a ed.)

OJAKANGAS, Richard W. The Earth, Past and Present - Richard W. Ojakangas, David G. Darby. McGraw-Hill, 1976.

Cita MLA (8a ed.)

OJAKANGAS, Richard W. The Earth, Past and Present - Richard W. Ojakangas, David G. Darby. McGraw-Hill, 1976.