@misc{indiciaea3a28d52d2fd,
  title = {Aeromagnetic map of the Perkiomenville quadrangle, Montgomery and Bucks Counties, Pennsylvania},
  author = {Randolph Wilson Bromery and G. L. Zandle},
  year = {1959},
  doi = {10.3133/gp208},
  url = {https://pubs.usgs.gov/publication/gp208},
  note = {Source identifier: gp208}
}