@misc{indiciaeb06f87d67d90,
  title = {Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory-Determination of ammonium plus organic nitrogen by a Kjeldahl digestion method and an automated photometric finish that includes digest cleanup by gas diffusion},
  author = {Charles J. Patton and Earl P. Truitt},
  year = {2000},
  doi = {10.3133/ofr00170},
  url = {https://pubs.usgs.gov/publication/ofr00170},
  note = {Source identifier: ofr00170}
}