@misc{indiciae50342fd65c1e,
  title = {Borehole geophysics applied to ground-water investigations},
  author = {W.S. Keys},
  year = {1990},
  doi = {10.3133/twri02e2},
  url = {https://pubs.usgs.gov/publication/twri02E2},
  note = {Source identifier: twri02E2}
}