A syllabus of Pennsylvania geology and mineral resources / by George H. Ashley.Ashley, Geo. H. (George Hall), 1866-1951. · First published 1931Open the Tome
Punxsutawney quadrangle; geology and mineral resources / by George H. Ashley. Prepared in cooperation with the United States Geological surveyAshley, Geo. H. (George Hall), 1866-1951. · First published 1926Open the Tome
The story of the Pennsylvania survey / by George H. Ashley.Ashley, Geo. H. (George Hall), 1866-1951. · First published 1921Open the Tome
Establishment, Purpose, Scope and Methods of the State Geological SurveyGeorge Hall Ashley · First published 1910Open the Tome
Oil and Gas Fields of PennsylvaniaGeorge Hall Ashley, J French Robinson · First published 2018Open the Tome
The scenery of PennsylvaniaAshley, Geo. H. (George Hall), 1866-1951 · First published 1933Open the Tome
The story of the Pennsylvania surveyAshley, Geo. H. (George Hall), b. 1866. · First published 1921Open the Tome
Drainage Reclamation in Tennessee, First Papers: Drainage Peoblems [!] in ...Tennessee State Geological Survey, George Hall Ashley · First published 1910Open the Tome
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