TY  - RPRT
TI  - Preliminary structural map showing contours on the horizon of number 9 coal in the Henderson area, Kentucky
AU  - E.J. Harvey
PY  - 1951
DO  - 10.3133/ofr51114
UR  - https://pubs.usgs.gov/publication/ofr51114
ID  - ofr51114
ER  -