@TECHREPORT {SEs01a,
     AUTHOR = {Sleijpen, Gerard L. G. and 
               {van den Eshof}, Jasper},
      TITLE = {Accurate approximations to eigenpairs using the 
               harmonic {R}ayleigh-{R}itz method},
       TYPE = {Preprint},
     NUMBER = {1184},
INSTITUTION = {Dep. Math., University Utrecht},
    ADDRESS = {Utrecht, the Netherlands},
      MONTH = {April},
       YEAR = {2001},}

@ARTICLE {SEs01,
   AUTHOR = {Sleijpen, Gerard L. G. and 
               {van den Eshof}, Jasper},
    TITLE = {Accurate approximations to eigenpairs using the 
               harmonic {R}ayleigh-{R}itz method},
  JOURNAL = {Linear Algebra Appl.},
 FJOURNAL = {Linear Algebra and its Applications},
   VOLUME = {358},
     YEAR = {2003},
   NUMBER = {1-3},
    PAGES = {115-137},}