Hamidi, Saad, Jamal Mohammed, and Laith Reda. “Design and Implementation of an Automatic Control for Two Axis Tracking System for Applications of Concentrated Solar Thermal Power”. Al-Khwarizmi Engineering Journal 14, no. 4 (December 1, 2018): 54- 63. Accessed August 14, 2021. https://alkej.uobaghdad.edu.iq/index.php/alkej/article/view/58.