@misc{indiciae49c8e5130aed,
  title = {Aeromagnetic map of the Sassamansville quadrangle, Montgomery and Berks Counties, Pennsylvania},
  author = {Randolph Wilson Bromery and G. L. Zandle},
  year = {1959},
  doi = {10.3133/gp207},
  url = {https://pubs.usgs.gov/publication/gp207},
  note = {Source identifier: gp207}
}