@MISC\{IMM2004-03223,
    author       = "N. H. Pontoppidan",
    title        = "Condition monitoring with unsupervised learning",
    year         = "2004",
    month        = "may",
    publisher    = "Informatics and Mathematical Modelling, Technical University of Denmark, {DTU}",
    address      = "Richard Petersens Plads, Building 321, {DK-}2800 Kgs. Lyngby",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/3223-full.html"
}