@misc{indiciaeee6361b7713e,
  title = {Relation of nitrogen and phosphorus in ground water to land use in four subunits of the Potomac River basin},
  author = {S.W. Ator and J. M. Denis},
  year = {1997},
  doi = {10.3133/wri964268},
  url = {https://pubs.usgs.gov/publication/wri964268},
  note = {Source identifier: wri964268}
}