@misc{indiciae25c0d269637c,
  title = {Atlas of urban and regional change, greater Pittsburgh region, Pennsylvania; B, Census Tracts, 1970},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1976},
  doi = {10.3133/ofr7528b},
  url = {https://pubs.usgs.gov/publication/ofr7528B},
  note = {Source identifier: ofr7528B}
}