@misc{indiciaedde758788641,
  title = {Phosphate rock demand into the next century: Impact on wolld food supply},
  author = {J. R. Herring and R.J. Fantel},
  year = {1993},
  doi = {10.1007/bf02257917},
  url = {https://pubs.usgs.gov/publication/70017383},
  note = {Source identifier: 70017383}
}