Guo, Xiwen, Xianda Liao, Qunjing Wang, Yan Wen, and Tao Wu. 2022. “Designing Active Disturbance Rejection Control of Permanent Magnetic Spherical Actuator Based on Nonlinear Extended State Observer”. Elektronika Ir Elektrotechnika 28 (1):23-31. https://doi.org/10.5755/j02.eie.30102.