@misc{indiciaefbbcb5a5e53c,
  title = {Geology of phosphate deposits of northern peninsular Florida},
  author = {Gilbert H. Espenshade and Charles Winthrop Spencer},
  year = {1963},
  doi = {10.3133/b1118},
  url = {https://pubs.usgs.gov/publication/b1118},
  note = {Source identifier: b1118}
}