1. C. C. Hang, K. J. & Aström and Q. G. Wang, Relay feedback auto-tuning of process controllers - a tutorial review, Journal of Process Control, 12 (2002) 143-162.
2. K. J. Aström, T. H. Lee, K. K. Tan and K. H. Johansson, “Recent advances in relay feedback methods - a survey”, in Proc. of the IEEE International Conference on Systems, Man and Cybernetics (Intelligent Systems for the 21st Century), Vol. 3. 1995.
3. Non-parametric tuning of PID controllers: a modified relay-feedback-test approach;Boiko,2013
4. Fractional order integrator for the relay feedback identification of a process Nyquist point in the third quadrant, Korean J;Byeon;Chem. Eng.,2011
5. I. Podlubny, “Fractional-order models: a new stage in modeling and control”. In Proc. of the IFAC Conference on System Structure and Control, July 8-10, 1998, Nantes, France, Vol. 2, pp. 231-235.