"On aggressive early deflation in parallel variants of the QR algorithm"
Bo Kågström, Daniel Kressner, and Meiyue Shao
(PARA 2010) Applied Parallel and Scientific Computing,
Lecture Notes in Computer Science, Volume 7133, 1–10, 2012.
Also available as Technical Report, UMINF-10.13, Department of Computing
Science and HPC2N, Umeå University, 2010.