@misc{indiciae9de7b0e87c8e,
  title = {Total intensity aeromagnetic map of Allen County, Indiana},
  author = {John R. Henderson and J. L. Meuschke},
  year = {1950},
  doi = {10.3133/gp21},
  url = {https://pubs.usgs.gov/publication/gp21},
  note = {Source identifier: gp21}
}