@misc{indiciae0882d716c172,
  title = {Estimated anthropogenic nitrogen and phosphorus inputs to the land surface of the conterminous United States--1992, 1997, and 2002},
  author = {Lori A. Sprague and Jo Ann M. Gronberg},
  year = {2013},
  doi = {10.3133/sir20125241},
  url = {https://pubs.usgs.gov/publication/sir20125241},
  note = {Source identifier: sir20125241}
}