TY  - RPRT
TI  - Formation and distribution of coal balls in the Herrin Coal (Pennsylvanian), Franklin County, Illinois Basin, USA
AU  - P.J. DeMaris
PY  - 2022
DO  - 10.1144/jgs.157.1.221
UR  - https://pubs.usgs.gov/publication/70022249
ID  - 70022249
ER  -