@misc{indiciaeabd98acf150c,
  title = {A Procedure for the supercritical fluid extraction of coal samples, with subsequent analysis of extracted hydrocarbons},
  author = {Jonathan J. Kolak},
  year = {2006},
  doi = {10.3133/ofr20061054},
  url = {https://pubs.usgs.gov/publication/ofr20061054},
  note = {Source identifier: ofr20061054}
}