TY  - BOOK
AU  - Stone,Ralph W.
TI  - The minerals of Pennsylvania: Non-metallic minerals,
AV  - TN24.P4 A7
PY  - 1939///
CY  - Harrisburg, Pa.
PB  - Department of Internal Affairs, Topographic and Geologic Survey
KW  - Mines and mineral resources
KW  - Pennsylvania
N1  - At head of title: Pennsylvania Geological survey, Fourth series; With Ashley, G. H. The undeveloped mineral resources of Pennsylvania. 1933. (Bulletin M18-A); Bibliographical footnotes
ER  -