@misc{indiciae5a4d68a354d3,
  title = {Our mineral supplies--Barium and strontium},
  author = {J. M. Hill},
  year = {1919},
  doi = {10.3133/b666w},
  url = {https://pubs.usgs.gov/publication/b666W},
  note = {Source identifier: b666W}
}