@misc{indiciae1b4fe33bd068,
  title = {Aeromagnetic map of the Lansdale quadrangle, Montgomery County, Pennsylvania},
  author = {Randolph Wilson Bromery and G. L. Zandle and and others},
  year = {1960},
  doi = {10.3133/gp264},
  url = {https://pubs.usgs.gov/publication/gp264},
  note = {Source identifier: gp264}
}