@misc{indiciae430fa1ea1cbc,
  title = {Ground-water levels on the south coast of Puerto Rico, February 1976},
  author = {J. E. Heisel and J.R. Gonzalez},
  year = {1976},
  doi = {10.3133/ofr76705},
  url = {https://pubs.usgs.gov/publication/ofr76705},
  note = {Source identifier: ofr76705}
}