@misc{indiciae576806e1b053,
  title = {Schlumberger sounding results and the altitude of the Pierre Shale at the Pueblo Chemical Depot, Pueblo, Colorado},
  author = {R.J. Bisdorf},
  year = {1998},
  doi = {10.3133/ofr98490},
  url = {https://pubs.usgs.gov/publication/ofr98490},
  note = {Source identifier: ofr98490}
}