@misc{indiciaedf11a66a23f7,
  title = {A Note on Multigrid Theory for Non-nested Grids and/or Quadrature},
  author = {Douglas, C. C. and Douglas, J., Jr. and Fyfe, D. E.},
  year = {1996},
  url = {https://ntrs.nasa.gov/citations/19970006876},
  note = {Source identifier: 19970006876}
}