Chuman, Tadchanon, and Suchin Arunsawatwong. “Criterion of Approximation for Designing 2 × 2 Feedback Systems with Inputs Satisfying Bounding Conditions”. ECTI Transactions on Electrical Engineering, Electronics, and Communications 13, no. 1 (November 11, 2014): 1–10. accessed August 30, 2026. https://ph02.tci-thaijo.org/index.php/ECTI-EEC/article/view/170968.