@misc{indiciae89f4e140d700,
  title = {Preconditioners for the spectral multigrid method},
  author = {Phillips, T. N. and Zang, T. A. and Hussaini, M. Y.},
  year = {1983},
  url = {https://ntrs.nasa.gov/citations/19830026391},
  note = {Source identifier: 19830026391}
}