@misc{indiciae3ef66275a7d7,
  title = {The appraisal of ore reserves at a Japanese copper mine},
  author = {John J. Collins},
  year = {1950},
  doi = {10.2113/gsecongeo.45.6.568},
  url = {https://pubs.usgs.gov/publication/70215315},
  note = {Source identifier: 70215315}
}