Quadcopter UAVs Extended States/Disturbance Observer-Based Nonlinear Robust Backstepping Control. - Ha Le Nhu Ngoc Thanh; Tuan-Tu Huynh; Mai The Vu; Nguyen Xuan Mung; Ngoc Phi Nguyen; Sung Kyung Hong; Truong Nguyen Luan Vu (Sensors, 2022)