@misc{indiciae2b1f1ae54e38,
  title = {Aeromagnetic map of western Pennsylvania and parts of eastern Ohio, northern West Virginia, and western Maryland},
  author = {Peter Popenoe and A. J. Petty and N.S. Tyson},
  year = {1964},
  doi = {10.3133/gp445},
  url = {https://pubs.usgs.gov/publication/gp445},
  note = {Source identifier: gp445}
}