TY  - RPRT
TI  - Summary map of mined areas and areas of potential coal mining, southwestern Pennsylvania
AU  - W. R. Kohl
AU  - R. P. Briggs
PY  - 1976
DO  - 10.3133/mf729
UR  - https://pubs.usgs.gov/publication/mf729
ID  - mf729
ER  -