@BOOK\{IMM1971-03742,
    author       = "V. V. Vidal",
    title        = "Operational Research in Production Planning",
    year         = "1971",
    pages        = "321",
    volume       = "",
    number       = "",
    series       = "",
    publisher    = "{IMSOR,} {DTH}",
    address      = "",
    edition      = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/3742-full.html"
}