@article {LieStr08,
    AUTHOR = {Liesen, J{\"o}rg and Strako{\v{s}}, Zden{\v e}k},
     TITLE = {On optimal short recurrences for generating orthogonal 
              Krylov subspace bases},
   JOURNAL = {SIAM Rev.},
  FJOURNAL = {SIAM Review},
    VOLUME = {50},
      YEAR = {2008},
    NUMBER = {3},
     PAGES = {485--503},
}