@misc{indiciae346d99504d85,
  title = {Mixing of shallow and deep groundwater as indicated by the chemistry and age of karstic springs},
  author = {D. J. Toth and B. G. Katz},
  year = {2006},
  doi = {10.1007/s10040-005-0478-x},
  url = {https://pubs.usgs.gov/publication/70031022},
  note = {Source identifier: 70031022}
}