1. When old is new again;Putman;Videosystems,2002
2. B.Wendler, LED Viewing Angles vs. LED Video Display Viewing Angles, Technical Note 40, Daktronics Inc., 2002.
3. Light-Emitting Diodes;Schubert,2003
4. The Radiometry of Light Emitting Diodes, Technical Guide, Labsphere Inc., 2001.
5. LED Metrology, Handbook of LED Metrology, Instrument Systems GmbH, 2000.