TY  - RPRT
TI  - Structure contour map of the Pittsburgh coal bed, southwestern Pennsylvania and northern West Virginia
AU  - John B. Roen
AU  - Deborah E. Farrel
PY  - 1973
DO  - 10.3133/ofr73244
UR  - https://pubs.usgs.gov/publication/ofr73244
ID  - ofr73244
ER  -