@misc{indiciae4a160a5b08cf,
  title = {13C-NMR spectra and contact time experiment for Skjervatjern fulvic and humic acids},
  author = {Ronald L. Malcolm},
  year = {1992},
  doi = {10.1016/0160-4120(92)90028-3},
  url = {https://pubs.usgs.gov/publication/70016823},
  note = {Source identifier: 70016823}
}