@misc{indiciae16a81a5e20cd,
  title = {Quartz crystal in Brazil},
  author = {W. D. Johnston and R.D. Butler},
  year = {1946},
  doi = {10.1130/0016-7606(1946)57[601:qcib]2.0.co;2},
  url = {https://pubs.usgs.gov/publication/70215038},
  note = {Source identifier: 70215038}
}