TY  - RPRT
TI  - Fluorospar Investigations: Preliminary Report on the Geology of the Columbia Mine Area, Crittenden County, Kentucky
AU  - G. C. Hardin
PY  - 1944
DO  - 10.3133/ofr4411
UR  - https://pubs.usgs.gov/publication/ofr4411
ID  - ofr4411
ER  -