@misc{indiciae530209cb7d14,
  title = {Aeromagnetic map of the Sinking Spring quadrangle, Berks and Lancaster Counties, Pennsylvania},
  author = {Randolph Wilson Bromery and G. L. Zandle},
  year = {1961},
  doi = {10.3133/gp240},
  url = {https://pubs.usgs.gov/publication/gp240},
  note = {Source identifier: gp240}
}