@article{etna_vol38_pp363-400,
  author  = {Paul R. Willems and Bruno Lang},
  title   = {Block factorizations and qd-type transformations for the $\mbox{MR}^3$ algorithm},
  journal = {Electron. Trans. Numer. Anal.},
  volume  = {38},
  year    = {2011},
  pages   = {363--400},
}