@misc{indiciaef863dfcc4839,
  title = {Geologic map of the San Juan quadrangle, Puerto Rico},
  author = {Maurice Henry Pease and Watson Hiner Monroe},
  year = {1975},
  doi = {10.3133/ofr75252},
  url = {https://pubs.usgs.gov/publication/ofr75252},
  note = {Source identifier: ofr75252}
}