@misc{indiciaef1497a1baeeb,
  title = {Contributions to economic geology (short papers and preliminary reports, 1930 : Part I. - Metals and nonmetals except fuels},
  author = {Gerald Francis Loughlin and E. F. Burchard},
  year = {1931},
  doi = {10.3133/b821},
  url = {https://pubs.usgs.gov/publication/b821},
  note = {Source identifier: b821}
}