@misc{indiciaea22de9ad9ea2,
  title = {A multigrid algorithm for the cell-centered finite difference scheme},
  author = {Ewing, Richard E. and Shen, Jian},
  year = {1993},
  url = {https://ntrs.nasa.gov/citations/19940017006},
  note = {Source identifier: 19940017006}
}