TY  - RPRT
TI  - Geologic map of the Heidrick quadrangle, Knox and Laurel Counties, Kentucky
AU  - Donald E. Trimble
AU  - J. Hiram Smith
PY  - 1978
DO  - 10.3133/gq1501
UR  - https://pubs.usgs.gov/publication/gq1501
ID  - gq1501
ER  -