S. Na'man, H. Y. Yacoob, and O. S. Omar, “Optimum Tilt Angle for South Facing Flat Solar Collectors in Duhok City”, SJUOZ, vol. 1, no. 1, pp. 405–413, Jun. 2013, Accessed: Apr. 16, 2026. [Online]. Available: https://sjuoz.uoz.edu.krd/index.php/sjuoz/article/view/98