@CONFERENCE\{IMM2004-03350,
    author       = "M. Fr{\"{a}}nzle and M. R. Hansen",
    title        = "A Robust Interpretation of Duration Calculus",
    year         = "2004",
    month        = "oct",
    keywords     = "Temporal logic, metric time, approximability",
    booktitle    = "Nordic Workshop on Programming Theory 2004",
    volume       = "",
    series       = "",
    editor       = "",
    publisher    = "Informatics and Mathematical Modelling, Technical University of Denmark, {DTU}",
    organization = "",
    address      = "Richard Petersens Plads, Building 321, {DK-}2800 Kgs. Lyngby",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/3350-full.html"
}