@TechReport{HPGS09,
  author       = "Hadim, Julien and Pacanowski, Romain and Granier, Xavier and Schlick, Christophe",
  title        = "Flat Bidirectional Texture Functions",
  institution  = "INRIA Bordeaux - Sud Ouest",
  number       = "	RR-7144",
  year         = "2009",
  url          = "http://iparla.labri.fr/publications/2009/HPGS09"
}