@misc{indiciae15fede42609b,
  title = {Vertical gradients in water chemistry and age in the southern High Plains Aquifer, Texas, 2002},
  author = {P.B. McMahon and J.K. Böhlke and T.M. Lehman},
  year = {2004},
  doi = {10.3133/sir20045053},
  url = {https://pubs.usgs.gov/publication/sir20045053},
  note = {Source identifier: sir20045053}
}