TY  - RPRT
TI  - Sturgis Formation (Upper Pennsylvanian), a new map unit in the western Kentucky coal field
AU  - Thomas M. Kehn
PY  - 1973
DO  - 10.3133/b1394b
UR  - https://pubs.usgs.gov/publication/b1394B
ID  - b1394B
ER  -