@misc{indiciaea90de297f92e,
  title = {Geologic map of the Yauco and Punta Verraco quadrangles, Puerto Rico},
  author = {R.D. Krushensky and W. H. Monroe},
  year = {1979},
  doi = {10.3133/i1147},
  url = {https://pubs.usgs.gov/publication/i1147},
  note = {Source identifier: i1147}
}