Shamseldin, M. A., Sallam, M., Bassiuny, A., & Ghany, A. A. (2026). Practical Implementation of an Enhanced Nonlinear PID Controller Based on Harmony Search for One-Stage Servomechanism System. Journal of Applied Nonlinear Dynamics, 9(2), 189-205. https://doi.org/10.5890/JAND.2020.06.003