@misc{indiciae86dad4979c40,
  title = {Multilevel filtering elliptic preconditioners},
  author = {Kuo, C. C. Jay and Chan, Tony F. and Tong, Charles},
  year = {1989},
  url = {https://ntrs.nasa.gov/citations/19910023531},
  note = {Source identifier: 19910023531}
}