@misc{indiciaeca55a7a04d81,
  title = {County-based estimates of nitrogen and phosphorus content of animal manure in the United States for 1982, 1987, and 1992},
  author = {Larry Puckett and Kerie Hitt and Richard Alexander},
  year = {1998},
  doi = {10.3133/70046661},
  url = {https://pubs.usgs.gov/publication/70046661},
  note = {Source identifier: 70046661}
}