@misc{indiciae2398805d8a5a,
  title = {Geology of the Comerio quadrangle, Puerto Rico},
  author = {M. H. Pease and R. P. Briggs},
  year = {1960},
  doi = {10.3133/i320},
  url = {https://pubs.usgs.gov/publication/i320},
  note = {Source identifier: i320}
}