TY  - BOOK
AU  - Ashley,GeoH.
TI  - The undeveloped mineral resources of Pennsylvania
T2  - Pennsylvania. Geological survey, 4th (1919-  ) Bulletin M18-A
AV  - TN24.P4 A7
PY  - 1933///
CY  - Harrisburg, Pa.
PB  - Department of internal affairs, Topographic and geologic survey
KW  - Mines and mineral resources
KW  - Pennsylvania
N1  - At head of title: Pennysylvania Geological survey, Fourth series
ER  -