@misc{indiciaeecd8097f14d4,
  title = {Geologic map and coal resources of The Gap SW Quadrangle, Campbell County, Wyoming},
  author = {S.L. Grazis},
  year = {1977},
  doi = {10.3133/coal78},
  url = {https://pubs.usgs.gov/publication/coal78},
  note = {Source identifier: coal78}
}