@misc{indiciaeac00b0637028,
  title = {Diagrams showing correlation of Paleocene coal beds underlying the Birney 1 degree x 1/2 degree quadrangle, Big Horn, Rosebud, and Powder River Counties, Montana},
  author = {William Craven Culbertson},
  year = {1980},
  doi = {10.3133/ofr80666},
  url = {https://pubs.usgs.gov/publication/ofr80666},
  note = {Source identifier: ofr80666}
}