@misc{indiciae037e79dd1511,
  title = {Aeromagnetic map of the Pottstown quadrangle, Berks, Chester, and Montgomery Counties, Pennsylvania},
  author = {Randolph Wilson Bromery and G. L. Zandle},
  year = {1960},
  doi = {10.3133/gp222},
  url = {https://pubs.usgs.gov/publication/gp222},
  note = {Source identifier: gp222}
}