@misc{indiciae016463995489,
  title = {Bottom sediment types of the northern insular shelf of Puerto Rico; Punta Penon to Punta Salinas},
  author = {O. H. Pilkey and D. M. Bush and R. W. Rodriguez},
  year = {1987},
  doi = {10.3133/i1861},
  url = {https://pubs.usgs.gov/publication/i1861},
  note = {Source identifier: i1861}
}