TY  - RPRT
TI  - Map showing areas that correlate with subsidence events due to underground mining of the Pittsburgh and Upper Freeport coal beds, Allegheny, Washington, and Westmoreland counties, Pennsylvania
AU  - K.O. Bushnell
PY  - 1975
DO  - 10.3133/mf693c
UR  - https://pubs.usgs.gov/publication/mf693C
ID  - mf693C
ER  -