@misc{indiciae3cf7842999e8,
  title = {A national look at nitrate contamination of ground water},
  author = {Bernard T. Nolan and Barbara C. Ruddy and Kerie J. Hitt and Dennis R. Helsel},
  year = {1998},
  url = {https://pubs.usgs.gov/publication/70046294},
  note = {Source identifier: 70046294}
}