@article{HSZ08,
     AUTHOR = {Hochstenbach, Michiel E. and Singer, David A. and Zachlin, Paul F.},
      TITLE = {Eigenvalue inclusion regions from inverses of shifted matrices},
    JOURNAL = {Linear Algebra Appl.},
   FJOURNAL = {Linear Algebra and its Applications},
     VOLUME = {429(10)},
      PAGES = {2481--2496},
    MRCLASS = {65F15, 65F50},   
       YEAR = {2008},
}