@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}, }