1. Burnside, C. D., [Electromagnetic Distance Measurement], BSP Professional Books, third ed. (1991).
2. A two-hundred-foot yardstick with graduations every microinch;Dukes;Hewlett-Packard Journal,1970
3. A new tool for old measurements–and new ones too;Rudé;Hewlett-Packard Journal,1970
4. An instant-on laser for length measurement;Burgwald;Hewlett-Packard Journal,1970
5. Meier, D., Dave Meier’s HP Laser Interferometer Evolution Page. http://www.n4mw.com/hp5526/hple.htm.