@misc{indiciae39d84218f310,
  title = {County-level estimates of nutrient inputs to the land surface of the conterminous United States, 1982-2001},
  author = {Barbara C. Ruddy and David L. Lorenz and David K. Mueller},
  year = {2006},
  doi = {10.3133/sir20065012},
  url = {https://pubs.usgs.gov/publication/sir20065012},
  note = {Source identifier: sir20065012}
}