@misc{indiciaecc2a8dbc5bd2,
  title = {A modular three-dimensional finite-difference ground-water flow model},
  author = {M.G. McDonald and A.W. Harbaugh},
  year = {1984},
  doi = {10.3133/ofr83875},
  url = {https://pubs.usgs.gov/publication/ofr83875},
  note = {Source identifier: ofr83875}
}