@misc{indiciae1ff4fe4601fc,
  title = {Calculation and use of ion activity},
  author = {John David Hem},
  year = {1961},
  doi = {10.3133/wsp1535c},
  url = {https://pubs.usgs.gov/publication/wsp1535C},
  note = {Source identifier: wsp1535C}
}