@misc{indiciaebb31acd90788,
  title = {Ground water in the San Juan metropolitan area, Puerto Rico},
  author = {H. R. Anderson},
  year = {1976},
  doi = {10.3133/wri7541},
  url = {https://pubs.usgs.gov/publication/wri7541},
  note = {Source identifier: wri7541}
}