@misc{indiciae9df4f38489a1,
  title = {Aeromagnetic map of Baltimore County and Baltimore City, Maryland},
  author = {R. W. Bromery},
  year = {1967},
  doi = {10.3133/gp613},
  url = {https://pubs.usgs.gov/publication/gp613},
  note = {Source identifier: gp613}
}