Quantile Regression Varying-Coefficient Model in The Case of Longitudinal Data: A Study on The Success Rates of Secondary Schools in Al-Diwaniyah Governorate \ Iraq. KJEAS [انترنت]. 12 مارس، 2025 [وثق 4 أكتوبر، 2026];17(56):1097-111. موجود في: https://kjeas.uowasit.edu.iq/index.php/kjeas/article/view/1393