@misc{indiciaec549517111f9,
  title = {Fluoride content of ground water in the conterminous United States (Maximum reported value for each county)},
  author = {Michael Fleischer},
  year = {1962},
  doi = {10.3133/i387},
  url = {https://pubs.usgs.gov/publication/i387},
  note = {Source identifier: i387}
}