@misc{indiciae4812643df756,
  title = {Complexes of ferrous iron with tannic acid},
  author = {John David Hem},
  year = {1960},
  doi = {10.3133/wsp1459d},
  url = {https://pubs.usgs.gov/publication/wsp1459D},
  note = {Source identifier: wsp1459D}
}