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1
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2Published 1986“...The Survey,...”
Government Document Book -
3Published 1900“...The Survey ;...”
Government Document Map -
4Published 1987“...The Survey,...”
Government Document Microform Map -
5Published 1990“...The Survey ;...”
Government Document Map -
6Published 1990“...The Survey ;...”
Government Document Map -
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17Published 1973“...Pennsylvania Geological Survey,...”
Book -
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