Cooper, J. D. (1986). A Trip Through Time: Principle Of Historical Geology. Merril Publishing Company.
Chicago-viite (17. p.)Cooper, John D. A Trip Through Time: Principle Of Historical Geology. Merril Publishing Company, 1986.
MLA-viite (8. p.)Cooper, John D. A Trip Through Time: Principle Of Historical Geology. Merril Publishing Company, 1986.
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