Ali, Saadi Ahmed, and Yassin Hameed Aial. “Differential Performance Ability Level Two-Parameter Model Paragraph Responses Theory”. Al-Adab Journal 2, no. 138 (September 15, 2021): 137–162. Accessed April 14, 2025. https://aladabj.uobaghdad.edu.iq/index.php/aladabjournal/article/view/1744.