Mahmood, Abbas Jumma. “The Role of Etiquette in Improving Employee Social Behavior : Questionnaire of Employees at Sulaimani International Airport”. The Scientific Journal of Cihan University– Sulaimaniya 5, no. 2 (April 15, 2022): 67-85. Accessed February 12, 2026. https://journal.sulicihan.edu.krd/index.php/sjcus/article/view/75.