@CONFERENCE\{IMM1993-01879,
    author       = "Z. Chaochen and A. P. Ravn and M. R. Hansen",
    title        = "An Extended Duration Calculus for Hybrid Systems",
    year         = "1993",
    pages        = "36-59",
    booktitle    = "Hybrid Systems",
    volume       = "736",
    series       = "LNCS",
    editor       = "R. L. Grossman and A. Nerode and A. P. Ravn and H. Rischel",
    publisher    = "Springer-Verlag",
    organization = "",
    address      = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/1879-full.html"
}