@CONFERENCE\{IMM1999-04020,
    author       = "H. Poulsen and K. K. Andersen and O. Paulsen",
    title        = "Optimum control of in-direct heating systems",
    year         = "1999",
    booktitle    = "World wide workshop of District Heating Control '991999",
    volume       = "",
    series       = "",
    editor       = "",
    publisher    = "",
    organization = "",
    address      = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/4020-full.html"
}