1. Apex Microtechnology, 5980 N. Shannon Road Tucson, AZ 85741-5230. Available from: http://www.teamapex.com
2. dSPACE Inc. 22260 Haggarty Road, Suite 120, Northville, MI 48167. Available from: http://www.dspaceinc.com
3. Active Control of Vibration;Fuller,1997
4. OYO GEOSPACE Corporation, 12750 South Kirkwood Suite 200, Stafford, TX 77477. Available from: http://www.oyo.com
5. The MathWorks Inc. 3 Apple Hill Drive Natick, MA 01760-2098. Available from: http://www.mathworks.com