American Institute of Professional Geologists. (1979). The Professional geologist. American Institute of Professional Geologists.
Cita Chicago Style (17a ed.)American Institute of Professional Geologists. The Professional Geologist. [Golden, Colo.]: American Institute of Professional Geologists, 1979.
Cita MLA (9a ed.)American Institute of Professional Geologists. The Professional Geologist. American Institute of Professional Geologists, 1979.
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