@misc{indiciae6a09ebb60bd1,
  title = {Mineral resources of the Black Rock Wilderness Study Area, Graham County, Arizona},
  author = {Frank S. Simons and P. K. Theobald and R.R. Tidball and J. A. Erdman and T. F. Harms and Andrew Griscom and G. S. Ryan},
  year = {1987},
  doi = {10.3133/b1703c},
  url = {https://pubs.usgs.gov/publication/b1703C},
  note = {Source identifier: b1703C}
}