1. Automatic tuning of PID controllers,;Åström,1988
2. Automatic tuning of PID regulators;Clarke,1986
3. Multivariable tuning regulators: The feedforward and robust control of general servo-mechanism problem;Davison;IEEE Trans Aut. Control,1976
4. Multivariable frequency domain toolbox - User’s Guide;Ford,1988
5. Tuning of multivariable Pi-controllers for unknown delay-differential systems;Jussila;IEEE Trans. Aut. Control,1987