@ARTICLE\{IMM1991-0331,
    author       = "H. Juel",
    title        = "On puzzle contests in {MS}/{OR} education",
    year         = "1991",
    pages        = "93",
    journal      = "Interfaces",
    volume       = "21",
    editor       = "",
    number       = "",
    publisher    = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/331-full.html"
}