@misc{indiciaebf1dfce33bdc,
  title = {Characterization of the International Humic Substances Society standard and reference fulvic and humic acids by solution state carbon-13 (13C) and hydrogen-1 (1H) nuclear magnetic resonance spectrometry},
  author = {Kevin A. Thorn and Daniel W. Folan and Patrick MacCarthy},
  year = {1989},
  doi = {10.3133/wri894196},
  url = {https://pubs.usgs.gov/publication/wri894196},
  note = {Source identifier: wri894196}
}