@misc{indiciaefc72b4950c13,
  title = {Hydrogeologic framework and generalized shallow ground-water circulation system, Allegheny County, Pennsylvania},
  author = {Seymour Subitzky},
  year = {1975},
  doi = {10.3133/mf641b},
  url = {https://pubs.usgs.gov/publication/mf641B},
  note = {Source identifier: mf641B}
}