@misc{indiciaee12adb5f4476,
  title = {A critical review of published coal quality data from the southwestern part of the Powder River Basin, Wyoming},
  author = {James A. Luppens},
  year = {2011},
  doi = {10.3133/ofr20111148},
  url = {https://pubs.usgs.gov/publication/ofr20111148},
  note = {Source identifier: ofr20111148}
}