Al-Mayahi, Wafaa, and Hassanin Al-Fahaam. “A Novel Variable Stiffness Compound Extensor-Pneumatic Artificial Muscle (CE-PAM): Design and Mathematical Model”. Journal of Robotics and Control (JRC) 4, no. 3 (June 2, 2023): 342–355. Accessed September 22, 2025. https://journal.umy.ac.id/index.php/jrc/article/view/18225.