@CONFERENCE\{IMM2000-02213,
    author       = "O. Bang and C. B. Clausen and L. Torner",
    title        = "Engineering of effective quadratic and cubic nonlinearities
 in two-period {QPM} gratings",
    year         = "2000",
    pages        = "147-148",
    booktitle    = "In Conference on Lasers and Electro-Optics, {OSA} Technical Digest, Optical Society of America",
    volume       = "",
    series       = "",
    editor       = "",
    publisher    = "",
    organization = "",
    address      = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/2213-full.html"
}