1. UB16 Precision Optical Length Measurement System, UBM Messtechnik GmbH, Ottostrasse 2, D-7505 Ettlingen, Germany
2. Rodenstock RM 600 Laser Stylus, Optische Werke G. Rodenstock, P.O. Box 140440, D-8000 München 5, Germany
3. Rodenstock RM 400, Rodenstock Optische Werke G. Rodenstock, P.O. Box 140440, D-8000 München 5, Germany
4. Talyfine, Rank Taylor Hobson Ltd, P.O. Box 36, Leicester LE2 0SL, England
5. Principles of Optical Disc Systems;Bouwhuis,1985