@misc{indiciaece7e161aa18b,
  title = {Two preliminary aeromagnetic maps covering Johnson and Marion Counties, Indiana},
  author = {John R. Henderson},
  year = {1950},
  doi = {10.3133/ofr5038},
  url = {https://pubs.usgs.gov/publication/ofr5038},
  note = {Source identifier: ofr5038}
}