Pratt, W. P. (1995). The Midcontinent strategic and critical minerals project. US Geological Survey circular 1124.
Chicago Style CitationPratt, Walden P. "The Midcontinent Strategic and Critical Minerals Project." US Geological Survey Circular 1124 1995.
MLA citiranjePratt, Walden P. "The Midcontinent Strategic and Critical Minerals Project." US Geological Survey Circular 1124 1995.
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