@misc{indiciae9437d67cd74e,
  title = {Copper resources in secondary enrichment blankets at Tanama, Puerto Rico},
  author = {D. P. Cox},
  year = {1992},
  doi = {10.3133/ofr92578},
  url = {https://pubs.usgs.gov/publication/ofr92578},
  note = {Source identifier: ofr92578}
}