@misc{indiciae91a6cb32c094,
  title = {Plan of study to determine if the isotopic ratios [delta]15 N and [delta]18 O can reveal the sources of nitrate discharged by the Mississippi River into the Gulf of Mexico},
  author = {William A. Battaglin and Carol Kendall and Donald A. Goolsby and Laurie L. Boyer},
  year = {1997},
  doi = {10.3133/ofr97230},
  url = {https://pubs.usgs.gov/publication/ofr97230},
  note = {Source identifier: ofr97230}
}