@CONFERENCE\{IMM1994-02781,
    author       = "M. Rostgaard and N. K. Poulsen and O. Ravn",
    title        = "ML-estimation for Delta Based State Space Models",
    year         = "1994",
    pages        = "663-668",
    booktitle    = "Identification and System Parameter Estimation (SYSID4), Copenhagen, Denmark",
    volume       = "3",
    series       = "",
    editor       = "",
    publisher    = "",
    organization = "",
    address      = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/2781-full.html"
}