@misc{indiciae25600268dc81,
  title = {Cretaceous and lower Tertiary stratigraphy in west-central Puerto Rico},
  author = {Peter H. Mattson},
  year = {1967},
  doi = {10.3133/b1254b},
  url = {https://pubs.usgs.gov/publication/b1254B},
  note = {Source identifier: b1254B}
}