@misc{indiciae20f9ff18508a,
  title = {National Water-Quality Assessment (NAWQA) Study-Unit Investigations in the conterminous United States 1991-2001},
  author = {K.J. Hitt and N. Nakagaki},
  year = {2006},
  doi = {10.3133/70046917},
  url = {https://pubs.usgs.gov/publication/70046917},
  note = {Source identifier: 70046917}
}