TY  - RPRT
TI  - Map of land modified by man in the Ambridge 7 1/2-minute Quadrangle, Allegheny County and vicinity, Pennsylvania
AU  - J. S. Pomeroy
PY  - 1974
DO  - 10.3133/ofr7474
UR  - https://pubs.usgs.gov/publication/ofr7474
ID  - ofr7474
ER  -