@misc{indiciae7bd720f79ce2,
  title = {Copper deposits of a part of the Helvetia mining district, Arizona},
  author = {S. C. Creasey and G.L. Quick},
  year = {1947},
  doi = {10.3133/ofr4715},
  url = {https://pubs.usgs.gov/publication/ofr4715},
  note = {Source identifier: ofr4715}
}