@ARTICLE\{IMM1991-02570,
    author       = "E. Arjas and C. K. Hansen and P. Thyregod",
    title        = "Heterogeneous part quality as a source of reliabiity improvement in repairable systems",
    year         = "1991",
    pages        = "1-12",
    journal      = "Technometrics",
    volume       = "33",
    editor       = "",
    number       = "",
    publisher    = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/2570-full.html"
}