@misc{indiciae1ba6714b0aca,
  title = {Determination of total sulfur in lichens by combustion-infrared analysis},
  author = {L. L. Jackson and E.E. Engleman and J. L. Peard},
  year = {1984},
  doi = {10.3133/ofr84656},
  url = {https://pubs.usgs.gov/publication/ofr84656},
  note = {Source identifier: ofr84656}
}