1. Ackermann, J., & Kaesbauer, D. (2001). Design of robust PID controllers, In Proceedings of European control conference, Porto.
2. Ackermann, J., Kaesbauer, D., & Bajcinca, N. (2002). Discrete-timerobust PID and three-term control. XV IFAC World Congress, Barcelona.
3. Bajcinca, N. (2001). The method of singular frequencies for robust design in an affine parameter space. Ninth mediterranean conference on control and automation, Dubrovnik.
4. Bajcinca, N., & Hulin, T. (2004). Robsin: A new tool for robust design of PID and three-term controllers based on singular frequencies. CACSD/ISIC/CCA, Taipei.
5. Structure and synthesis of PID controllers;Ho,2000