@misc{indiciae6e6636ce1207,
  title = {Application of classification-tree methods to identify nitrate sources in ground water},
  author = {T.B. Spruill and W.J. Showers and S. S. Howe},
  year = {2002},
  url = {https://pubs.usgs.gov/publication/70024306},
  note = {Source identifier: 70024306}
}