TY  - RPRT
TI  - Preliminary correlation chart of coal beds and key beds of the Pennsylvanian rocks of eastern Kentucky
AU  - Charles L. Rice
AU  - J. Hiram Smith
PY  - 1979
DO  - 10.3133/ofr79867
UR  - https://pubs.usgs.gov/publication/ofr79867
ID  - ofr79867
ER  -