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
Outline Introduction to the Mineral Resources of TennesseeGeorge H. Ashley · First published 2023Open the Tome
Establishment, Purpose, Scope and Methods of the State Geological SurveyGeorge H. Ashley · First published 1910Open the Tome
The story of the Pennsylvania surveyAshley, Geo. H. (George Hall), b. 1866. · First published 1921Open the Tome
