“A Review of Hierarchical Routing Protocols in Wireless Sensor Networks: Types and Recent Developments”. Al-Rafidain Engineering Journal (AREJ) 30, no. 2 (September 1, 2025): 1–15. Accessed September 22, 2026. https://rengj.uomosul.edu.iq/index.php/rengj/article/view/53853.