@misc{indiciaedd8a4cd2322b,
  title = {Ground-water levels in the United States, 1972-74, north-central states},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1977},
  doi = {10.3133/wsp2163},
  url = {https://pubs.usgs.gov/publication/wsp2163},
  note = {Source identifier: wsp2163}
}