Ngamsom, Pinit. “Enhancing Disturbance Rejection of PID Controllers for DC Joint Motors of Trajectory Tracking Robots Using Disturbance Observer”. Applied Science and Engineering Progress 16, no. 4 (October 4, 2023): 6718. accessed December 9, 2025. https://ph02.tci-thaijo.org/index.php/ijast/article/view/250756.