@misc{indiciae6f954e644d80,
  title = {Telluric profiling studies in the Penrose area, Colorado},
  author = {Karen R. Christopherson and Kevin H. Nervick and William D. Heran},
  year = {1981},
  doi = {10.3133/ofr81461},
  url = {https://pubs.usgs.gov/publication/ofr81461},
  note = {Source identifier: ofr81461}
}