TY  - RPRT
TI  - Structure contour map of the base of the Pittsburgh coal bed, southwestern Pennsylvania and northern West Virginia
AU  - John B. Roen
AU  - Deborah E. Farrel
PY  - 1980
DO  - 10.3133/coal88
UR  - https://pubs.usgs.gov/publication/coal88
ID  - coal88
ER  -