@article{etna_vol44_pp327-341,
  author  = {Jared L. Aurentz and Thomas Mach and Raf Vandebril and David S. Watkins},
  title   = {Fast and stable unitary QR algorithm},
  journal = {Electron. Trans. Numer. Anal.},
  volume  = {44},
  year    = {2015},
  pages   = {327--341},
}