@misc{indiciaeaad2b77bd304,
  title = {Preliminary geologic map of the Happy Valley quadrangle, Cochise County, Arizona},
  author = {Harald D. Drewes},
  year = {1972},
  doi = {10.3133/ofr7295},
  url = {https://pubs.usgs.gov/publication/ofr7295},
  note = {Source identifier: ofr7295}
}