@misc{indiciae9dd93b192115,
  title = {Geology of the middle Tertiary formations of Puerto Rico},
  author = {Watson Hiner Monroe},
  year = {1975},
  doi = {10.3133/ofr75313},
  url = {https://pubs.usgs.gov/publication/ofr75313},
  note = {Source identifier: ofr75313}
}