Ojakangas, R. W., & Darby, D. G. (1976). The earth: :Past and present. Mc Graw Hills.
Chicago Edition CitationOjakangas, Richard W., and David G. Darby. The Earth: :Past and Present. New York: Mc Graw Hills, 1976.
Deismireacht MLAOjakangas, Richard W., and David G. Darby. The Earth: :Past and Present. Mc Graw Hills, 1976.
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