@misc{indiciae0220959eb03e,
  title = {The uniqueness of humic substances in each of soil, stream and marine environments},
  author = {Ronald L. Malcolm},
  year = {1990},
  doi = {10.1016/s0003-2670(00)81222-2},
  url = {https://pubs.usgs.gov/publication/70016128},
  note = {Source identifier: 70016128}
}