1. T. Angot, J. Suzanne, J.Y. Hoarau, Rev. Sci. Instrum. 62, 1865 (1991)
2. K. Reichelt, Rev. Sci. Instrum. 44, 243 (1973)
3. T.S. Sriram, M.E. Fine, Y.-W. Chung, Rev. Sci. Instrum. 62, 2008 (1991)
4. Physik Instrumente, Model 243.37, Option 703.20, sold by PolyTec Optronics, 3001 Redhill Ave., Costa Mesa, CA 92626
5. Model 31, SENSOTE Inc., 1202 Chesapeake Ave., Columbus, OH 43212