@misc{indiciae07c96c2d208b,
  title = {Weight of Production of Emeralds, Rubies, Sapphires, and Tanzanite from 1995 Through 2005},
  author = {Thomas R. Yager and W. David Menzie and Donald W. Olson},
  year = {2008},
  doi = {10.3133/ofr20081013},
  url = {https://pubs.usgs.gov/publication/ofr20081013},
  note = {Source identifier: ofr20081013}
}