@techreport{brown2021world,
  title = {WORLD MINERAL PRODUCTION 2015–2019}
  author = {Brown, T J and Idoine, N E and Wrighton, C E and Raycraft, E R and Hobbs, S F and Everett, P and Deady, E A and Kresse, C},
  url = {Retrieved from https://www2.bgs.ac.uk/mineralsuk/download/world_statistics/2010s/WMP_2015_2019.pdf},
  year = {2021}
}