@misc{indiciaeb3d570c02c31,
  title = {A colloidal method for the concentration of carbonaceous matter from rocks},
  author = {Maurice Deul},
  year = {1955},
  doi = {10.3133/tei501},
  url = {https://pubs.usgs.gov/publication/tei501},
  note = {Source identifier: tei501}
}