@misc{indiciae8ef552c78927,
  title = {Thermal maturity and organic composition of Pennsylvanian coals and carbonaceous shales, north-central Texas: Implications for coalbed gas potential},
  author = {P.C. Hackley and E.H. Guevara and T.F. Hentz and R.W. Hook},
  year = {2009},
  doi = {10.1016/j.coal.2008.05.006},
  url = {https://pubs.usgs.gov/publication/70033042},
  note = {Source identifier: 70033042}
}