@article {ReesGreif2007,
    AUTHOR = {Rees, Tim and Greif, Chen},
     TITLE = {A preconditioner for linear systems arising from interior
              point optimization methods},
   JOURNAL = {SIAM J. Sci. Comput.},
  FJOURNAL = {SIAM Journal on Scientific Computing},
    VOLUME = {29},
      YEAR = {2007},
    NUMBER = {5},
     PAGES = {1992--2007}
}