@TECHREPORT {HSl01a,
     AUTHOR = {Sleijpen, Gerard L. G. and 
               {Hochstenbach}, Michiel},
      TITLE = {Two-sided and Alternating {J}acobi--{D}avidson},
       TYPE = {Preprint},
     NUMBER = {1196},
INSTITUTION = {Dep. Math., University Utrecht},
    ADDRESS = {Utrecht, the Netherlands},
      MONTH = {June},
       YEAR = {2001},}

@ARTICLE {HSl01,
   AUTHOR = {Sleijpen, Gerard L. G. and 
               {Hochstenbach}, Michiel},
    TITLE = {Two-sided and Alternating {J}acobi--{D}avidson},
  JOURNAL = {Linear Algebra Appl.},
 FJOURNAL = {Linear Algebra and its Applications},
   VOLUME = {358},
     YEAR = {2003},
   NUMBER = {1-3},
    PAGES = {145-172},}