@ARTICLE\{IMM2006-03290,
    author       = "B. Kallehauge and J. Larsen and O. B. G. Madsen",
    title        = "Lagrangian duality applied to the Vehicle Routing Problem with Time Windows",
    year         = "2006",
    pages        = "1464-1487",
    journal      = "Computers \& Operations Research",
    volume       = "33",
    editor       = "",
    number       = "5",
    publisher    = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/3290-full.html"
}