@TECHREPORT\{IMM1991-02788,
    author       = "B. G. Thygesen and N. K. Poulsen and J. Holst",
    title        = "Approximative results for the zero location in sampled dynamical systems",
    year         = "1991",
    number       = "16",
    series       = "",
    institution  = "Institute of Mathematical Statistics and Operations Research (IMSOR), The Technical University of Denmark",
    address      = "",
    type         = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/2788-full.html"
}