@misc{indiciae75f2fe4663be,
  title = {Hydrogeochemistry of the upper part of the Fort Union group in the Gascoyne lignite strip-mining area, North Dakota},
  author = {R. L. Houghton and Donald C. Thorstenson and Donald W. Fisher and G.H. Groenewold},
  year = {1987},
  doi = {10.3133/pp1340},
  url = {https://pubs.usgs.gov/publication/pp1340},
  note = {Source identifier: pp1340}
}