احمد ياسين عبدالرحمن. “An Econometrics Study of Estimate and Analyze a Cost Function for Beekeeping Fields in Halabja Governorate”. The Scientific Journal of Cihan University– Sulaimaniya 6, no. 1 (May 29, 2022): 299-310. Accessed February 12, 2026. https://journal.sulicihan.edu.krd/index.php/sjcus/article/view/107.