@misc{indiciae5743a7ce4a77,
  title = {Geologic map of the Orocovis Quadrangle, Puerto Rico},
  author = {R. P. Briggs},
  year = {1971},
  doi = {10.3133/i615},
  url = {https://pubs.usgs.gov/publication/i615},
  note = {Source identifier: i615}
}