@misc{indiciaeee6f9354f2d9,
  title = {Water-table map of Walworth County, Wisconsin},
  author = {Marvin G. Sherrill and John R. Erickson},
  year = {1978},
  doi = {10.3133/wri7942},
  url = {https://pubs.usgs.gov/publication/wri7942},
  note = {Source identifier: wri7942}
}