@misc{indiciaefa35992acd28,
  title = {C-13 NMR characterization of humic materials isolated by an MIBK partitioning procedure},
  author = {K. Thorn and J. Rice and R. Wershaw and P. MacCarthy},
  year = {1987},
  doi = {10.1016/0048-9697(87)90499-2},
  url = {https://pubs.usgs.gov/publication/70009895},
  note = {Source identifier: 70009895}
}