Ying Jian, Tan, and Zaharuddin Mohamed. “Modelling and Sway Control of a Double-Pendulum Overhead Crane System”. Applications of Modelling and Simulation, vol. 1, no. 1, Dec. 2017, pp. 15-21, https://www.ojs.arqiipubl.com/index.php/AMS_Journal/article/view/3.