@misc{indiciae291ed067fd9e,
  title = {Geologic map of the Yabucoa and Punta Tuna quadrangles, Puerto Rico},
  author = {Cleaves Lincoln Rogers and C. M. Cram and M. H. Pease and M. S. Tischler},
  year = {1977},
  doi = {10.3133/ofr77651},
  url = {https://pubs.usgs.gov/publication/ofr77651},
  note = {Source identifier: ofr77651}
}