The Multishift QR Algorithm. Part I: Maintaining Well-Focused Shifts and Level 3 Performance. - Karen Braman; Ralph Byers; Roy Mathias (SIAM J. Matrix Anal. Appl., 2002)

The Multishift QR Algorithm. Part II: Aggressive Early Deflation. - Karen Braman; Ralph Byers; Roy Mathias (SIAM J. Matrix Anal. Appl., 2002)