@misc{indiciaed1600fef8967,
  title = {Total intensity aeromagnetic map of Sullivan County, Indiana and part of Crawford County, Illinois},
  author = {John R. Henderson and J. L. Meuschke},
  year = {1951},
  doi = {10.3133/gp111},
  url = {https://pubs.usgs.gov/publication/gp111},
  note = {Source identifier: gp111}
}