@misc{indiciaedeb50e9312fa,
  title = {Ground-water resources of alluvial valleys in northeastern Puerto Rico—Rio Espiritu Santo to Rio Demajagua area},
  author = {Francisco Perez-Blair},
  year = {1997},
  doi = {10.3133/wri964201},
  url = {https://pubs.usgs.gov/publication/wri964201},
  note = {Source identifier: wri964201}
}