@misc{indiciae018d6420a52f,
  title = {A summary of niobium and rare earth localities from Ha'il and other areas in western Saudi Arabia: a preliminary study},
  author = {John J. Matzko and Mohammed Ibne Naqvi},
  year = {1978},
  doi = {10.3133/ofr78773},
  url = {https://pubs.usgs.gov/publication/ofr78773},
  note = {Source identifier: ofr78773}
}