@misc{indiciae818a099ef03b,
  title = {Documentation of a computer program to simulate horizontal-flow barriers using the U.S. Geological Survey's modular three-dimensional finite-difference ground-water flow model},
  author = {Paul A. Hsieh and John R. Freckleton},
  year = {1993},
  doi = {10.3133/ofr92477},
  url = {https://pubs.usgs.gov/publication/ofr92477},
  note = {Source identifier: ofr92477}
}