@misc{indiciae9d7e90555317,
  title = {Chemical analyses of lignite from the Sentinel Butte Member of the Fort Union Formation, Dunn Center Field, Dunn County, North Dakota},
  author = {Joseph R. Hatch and Ronald H. Affolter},
  year = {1978},
  doi = {10.3133/ofr781078},
  url = {https://pubs.usgs.gov/publication/ofr781078},
  note = {Source identifier: ofr781078}
}