TY  - BOOK
AU  - Ashley,GeoH.
TI  - A syllabus of Pennsylvania geology and mineral resources,
T2  - Pennsylvania Geological Survey. Bulletin G 1
PY  - 1931///
CY  - Harrisburg, Pa.
PB  - Topographic and Geologic Survey
KW  - Geology
KW  - Pennsylvania
KW  - Mines and mineral resources
N1  - "Pennsylvania Geological Survey. 4th series."
ER  -