@BOOK\{IMM1998-01902,
    author       = "M. R. Hansen",
    title        = "Duration Calculus: A Logical Approach to Real-Time Systems",
    year         = "1998",
    volume       = "",
    number       = "",
    series       = "",
    publisher    = "{DFKI} Saarbrücken",
    address      = "",
    edition      = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/1902-full.html"
}