@article {IOPORT.06031504,
    author       = {Benner, Peter and Mach, Thomas},
    title        = {Computing all or some eigenvalues of symmetric $\cal{H}_{\ell}$-matrices.},
    year         = {2012},
    journal      = {SIAM Journal on Scientific Computing},
    volume       = {34},
    number       = {1},
    issn         = {1064-8275},
    pages        = {A485-A496},
    publisher    = {Society for Industrial and Applied Mathematics (SIAM), Philadelphia, PA},
    doi          = {10.1137/100815323},
    identifier   = {06031504},
}