@misc{indiciae2fc47fd0ee45,
  title = {Risk of nitrate in groundwaters of the United States - A national perspective},
  author = {B. T. Nolan and B. C. Ruddy and K.J. Hitt and D.R. Helsel},
  year = {1997},
  doi = {10.1021/es960818d},
  url = {https://pubs.usgs.gov/publication/70019648},
  note = {Source identifier: 70019648}
}