@misc{indiciaed840254a427f,
  title = {Total intensity aeromagnetic map of De Kalb County, Indiana},
  author = {William J. Dempsey and John R. Henderson and R. T. Duffner},
  year = {1950},
  doi = {10.3133/gp23},
  url = {https://pubs.usgs.gov/publication/gp23},
  note = {Source identifier: gp23}
}