@INCOLLECTION\{IMM2004-02998,
    author       = "M. P. S{\o}rensen",
    title        = "Multiple scale analysis",
    year         = "2004",
    keywords     = "Perturbation theory, ordinary differential equations",
    edition      = "A.C. Scott",
    booktitle    = "Encyclopedia of Nonlinear Science",
    volume       = "",
    number       = "",
    series       = "",
    publisher    = "Fitzroy Dearborn Publishers",
    address      = "",
    edition      = "A.C. Scott",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/2998-full.html"
}