@misc{indiciae7f540428a845,
  title = {Geology of the manganese deposits of Cuba},
  author = {Frank S. Simons and John A. Straczek},
  year = {1958},
  doi = {10.3133/b1057},
  url = {https://pubs.usgs.gov/publication/b1057},
  note = {Source identifier: b1057}
}