@misc{indiciaea7358e6fff2e,
  title = {Aeromagnetic map of the Boyertown quadrangle, Berks and Montgomery Counties, Pennsylvania},
  author = {Randolph Wilson Bromery and G. L. Zandle},
  year = {1960},
  doi = {10.3133/gp232},
  url = {https://pubs.usgs.gov/publication/gp232},
  note = {Source identifier: gp232}
}