@misc{indiciae281bed789217,
  title = {Defining groundwater age},
  author = {T. Torgersen and R. Purtschert and F. M. Phillips and Niel Plummer and W. E. Sanford and A. Suckow},
  year = {2013},
  url = {https://pubs.usgs.gov/publication/70046478},
  note = {Source identifier: 70046478}
}