@misc{indiciae0d951f09f945,
  title = {A geochemical reconnaissance of the Island of Vieques, Puerto Rico},
  author = {Robert E. Learned and Ginny R. Grove and Rafael Boissen},
  year = {1973},
  doi = {10.3133/ofr73155},
  url = {https://pubs.usgs.gov/publication/ofr73155},
  note = {Source identifier: ofr73155}
}