1. Automatic tuning of simple regulators with specifications on phase and amplitude margins;Åström;Automatica,1984
2. Nonlinear control engineering;Atherton;Van Nostrand Reinhold,1982
3. Relay Autotuning for Identification and Control;Chidambaram,2014
4. Parameter estimation using relay feedback;Dharmalingam;Reviews in Chemical Engineering,2019
5. Multiple-input describing functions and nonlinear system design;Gelb,1968