Abrash, Michael. Michael Abrash's Graphics Programming Black Book Special Edition. The Coriolis Group, Scottsdale Arizona, 1997. ISBN1-57610-174-6 (PDFArchived 2007-03-11 at the Wayback Machine) (Chapter 70, pg. 1282)
Real-Time Bump Map Synthesis, Jan Kautz1, Wolfgang Heidrichy2 and Hans-Peter Seidel1, (1Max-Planck-Institut für Informatik, 2University of British Columbia)
Abrash, Michael. Michael Abrash's Graphics Programming Black Book Special Edition. The Coriolis Group, Scottsdale Arizona, 1997. ISBN1-57610-174-6 (PDFArchived 2007-03-11 at the Wayback Machine) (Chapter 70, pg. 1282)