@misc{indiciae51414a611a86,
  title = {Maps showing mined-out areas and property ownership, land-pebble phosphate district, Hillsborough and Polk Counties, Florida},
  author = {J.B. Cathcart and E.L.M. Ward},
  year = {1953},
  doi = {10.3133/ofr5335},
  url = {https://pubs.usgs.gov/publication/ofr5335},
  note = {Source identifier: ofr5335}
}