@TECHREPORT\{IMM2000-01109,
    author       = "H. W. Jensen and N. J. Christensen",
    title        = "Global illumination using photon maps",
    year         = "2000",
    number       = "",
    series       = "",
    institution  = "",
    address      = "",
    type         = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/1109-full.html"
}