@misc{indiciae2a3f8a5c67fd,
  title = {Steady state fractionation of heavy noble gas isotopes in a deep unsaturated zone},
  author = {Alan M. Seltzer and Jeffrey P. Severinghaus and Brian J. Andraski and David A. Stonestrom},
  year = {2017},
  doi = {10.1002/2016wr019655},
  url = {https://pubs.usgs.gov/publication/70188024},
  note = {Source identifier: 70188024}
}