The undeveloped mineral resources of Pennsylvania
By: introduction by George H. Ashley.
Series: Pennsylvania. Geological survey, 4th (1919-  ) Bulletin M18-A; Bulletin M ;; 18-A.
Publisher: Department of internal affairs, Topographic and geologic survey
Published: 1933
Place of publication: Harrisburg, Pa
Language: eng
Number of pages: 16
Subjects: Mines and mineral resources -- Pennsylvania.
Notes: At head of title: Pennysylvania Geological survey, Fourth series.