Mutar, Dr.Dhafir, and Mozahem Yehya. “Using Factor Analysis for Treatment Multicollinearity Problem and to Specifying the Effective Variables on the Wheat World Price”. TANMIYAT AL-RAFIDAIN 30, no. 91 (September 1, 2008): 202–222. Accessed January 18, 2026. https://tanmiyat.uomosul.edu.iq/index.php/tanmiyat/article/view/30028.