@misc{indiciae87189a1c350e,
  title = {Geologic map of the Carolina quadrangle, Puerto Rico},
  author = {Watson Hiner Monroe},
  year = {1977},
  doi = {10.3133/ofr77146},
  url = {https://pubs.usgs.gov/publication/ofr77146},
  note = {Source identifier: ofr77146}
}