Darby, R. W. O. a. D. G. The earth past and present. McGraw-Hill Book Company.
Chicago Style (17th ed.) CitationDarby, Richard W. Ojakangas and David G. The Earth Past and Present. McGraw-Hill Book Company.
MLA (8th ed.) CitationDarby, Richard W. Ojakangas and David G. The Earth Past and Present. McGraw-Hill Book Company.
Warning: These citations may not always be 100% accurate.