@misc{indiciae90c585243e7c,
  title = {Nitrogen flux and sources in the Mississippi River Basin},
  author = {D. A. Goolsby and W.A. Battaglin and Brent T. Aulenbach and R. P. Hooper},
  year = {2000},
  doi = {10.1016/s0048-9697(99)00532-x},
  url = {https://pubs.usgs.gov/publication/70022911},
  note = {Source identifier: 70022911}
}