1. Bryson, A. E. and Ho, Y. C., 1975,Applied Optimal Control, Hemisphere Pub. Co.
2. Doyle, J. C. and Stein, G., 1981, “Multivariable Feedback Design: Concepts for a Classical/Modern Synthesis,”IEEE Trans. on AC, Vol. 26, pp. 4–16.
3. Fabien, B. C., 1993, “Controller Gain Selection for an Electromagnetic Suspension Under Random Excitation,”ASME J. of Dyn. Sys. Meas. and Control, Vol. 115, pp. 156–165.
4. Fallside, F., 1977,Control System Design by Pole-Zero Assignment, Academic Press.
5. Kim, J. S., 1987, “Nonlinear Multivariable Control Using Statistical Linearization and Loop Transfer Recovery,” Ph. D. Thesis, Dept of Mech. Eng., MIT.