H. Abdoulqadir , Chia, and Farhad A. Mohammed. “ Spatial Distribution and Source Identification of Major and Trace Elements in Topsoil from Erbil Region, Iraq”. Tikrit Journal of Pure Science 30, no. 5 (October 25, 2025): 20–36. Accessed November 6, 2025. https://www.tjpsj.org/index.php/tjps/article/view/1783.