TY  - RPRT
TI  - Geologic map of the Gracey quadrangle, Trigg and Christian Counties, Kentucky
AU  - Willis H. Nelson
AU  - David Arthur Seeland
PY  - 1968
DO  - 10.3133/gq753
UR  - https://pubs.usgs.gov/publication/gq753
ID  - gq753
ER  -