@misc{indiciaed8095ee5602c,
  title = {Geologic map of the Fajardo and Cayo Icacos quadrangles, Puerto Rico},
  author = {R. P. Briggs and Eduardo Aguilar-Cortes},
  year = {1980},
  doi = {10.3133/i1153},
  url = {https://pubs.usgs.gov/publication/i1153},
  note = {Source identifier: i1153}
}