1. Plough, R. W., and Penzia, J., Dynamics of Structures, McGraw-Hill, New York, 1982, pp.160-165.
2. 2Craig, R. R., Jr., Structural Dynamics, Wiley, New York, 1981, pp.411-413.
3. 3Meirovitch, L., Analytical Methods in Vibration, MacMillan, New York, 1967, pp.262-270.
4. New generalized structural filtering concept for active vibration control synthesis