@misc{indiciae59d4f79c3e16,
  title = {Distinguishing black carbon from biogenic humic substances in soil clay fractions},
  author = {D.A. Laird and M.A. Chappell and D.A. Martens and R.L. Wershaw and M. Thompson},
  year = {2008},
  doi = {10.1016/j.geoderma.2007.10.025},
  url = {https://pubs.usgs.gov/publication/70033723},
  note = {Source identifier: 70033723}
}