@misc{indiciaea5f0a2f15963,
  title = {Ground Water Atlas of the United States: Segment 9, Iowa, Michigan, Minnesota, Wisconsin},
  author = {Perry G. Olcott},
  year = {1992},
  doi = {10.3133/ha730j},
  url = {https://pubs.usgs.gov/publication/ha730J},
  note = {Source identifier: ha730J}
}