@misc{indiciae86f04148964a,
  title = {Results of exploration at the Old Leyden coal mine, Jefferson County, Colorado},
  author = {A.J. Gude and F. A. McKeown},
  year = {1953},
  doi = {10.3133/ofr5382},
  url = {https://pubs.usgs.gov/publication/ofr5382},
  note = {Source identifier: ofr5382}
}