@misc{indiciae5e74265cc88c,
  title = {Aeromagnetic map of northeastern Illinois and its geologic interpretation},
  author = {M. E. Beck},
  year = {1965},
  doi = {10.3133/gp523},
  url = {https://pubs.usgs.gov/publication/gp523},
  note = {Source identifier: gp523}
}