@misc{indiciae668e39df98ed,
  title = {Philadelphia folio, Norristown, Germantown, Chester, and Philadelphia, Pennsylvania-New Jersey-Delaware},
  author = {Florence Bascom and W.B. Clark and N. H. Darton and G.N. Knapp and H.B. Kuemmel and B.L. Miller and R.D. Salisbury},
  year = {1909},
  doi = {10.3133/gf162},
  url = {https://pubs.usgs.gov/publication/gf162},
  note = {Source identifier: gf162}
}