@misc{indiciae6f2acae28cd9,
  title = {Chrome ores of southeastern Pennsylvania and Maryland. Deposits of chrome ore in North Carolina},
  author = {E. B. Knopf and J. V. Lewis},
  year = {1922},
  doi = {10.3133/b725b},
  url = {https://pubs.usgs.gov/publication/b725B},
  note = {Source identifier: b725B}
}