@misc{indiciaecff72ce0f754,
  title = {Map of land modified by man in the Pittsburgh West 7 1/2-minute Quadrangle, Allegheny County, Pennsylvania},
  author = {J. S. Pomeroy},
  year = {1974},
  doi = {10.3133/ofr74230},
  url = {https://pubs.usgs.gov/publication/ofr74230},
  note = {Source identifier: ofr74230}
}