@MISC\{IMM1997-01580,
    author       = "F. Nielson and et al.",
    title        = "Logical and Operational Methods in the Analysis of  Programs and Systems",
    year         = "1997",
    pages        = "1-21",
    publisher    = "Springer-Verlag",
    address      = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/1580-full.html"
}