@misc{indiciae35f83c8de547,
  title = {Geology and chemical analyses of coal and coal-associated rock samples, Williams Fork Formation (Upper Cretaceous), northwestern Colorado},
  author = {R.T. Hildebrand and R.S. Garrigues and R. F. Meyer and M.C. Reheis},
  year = {1981},
  doi = {10.3133/ofr811348},
  url = {https://pubs.usgs.gov/publication/ofr811348},
  note = {Source identifier: ofr811348}
}