Representations for the Drazin Inverse of a 2 x 2 Block Matrix

@article{Hartwig2005RepresentationsFT,
  title={Representations for the Drazin Inverse of a 2 x 2 Block Matrix},
  author={Robert Hartwig and Xiezhang Li and Yimin Wei},
  journal={SIAM J. Matrix Analysis Applications},
  year={2005},
  volume={27},
  pages={757-771}
}