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U.S. Geological Survey: Poster 1
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U.S. Geological Survey: Poster 4_003
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U.S. Geological Survey: Poster 9
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U.S. Geological Survey: Poster 17_002
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U.S. Geological Survey: Poster 20
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U.S. Geological Survey: Poster 28_002
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U.S. Geological Survey: Poster 34