@ARTICLE\{IMM1993-02741,
    author       = "J. Carstensen and H. Madsen and N. K. Poulsen and M. K. Nielsen",
    title        = "Grey box modelling in two time domains of a wastewater pilot scale plant",
    year         = "1993",
    pages        = "187-208",
    journal      = "Environmetrics",
    volume       = "4",
    editor       = "",
    number       = "",
    publisher    = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/2741-full.html"
}