@misc{indiciaea268a4a01437,
  title = {Geologic map of the Swisshelm Mountains, and a description of the development of the Swisshelm and Pedregosa Mountains, Cochise County, Arizona},
  author = {Harald Drewes},
  year = {1991},
  doi = {10.3133/i2177},
  url = {https://pubs.usgs.gov/publication/i2177},
  note = {Source identifier: i2177}
}