Khalil, Manar. " The Effect of Using the Six-dimensional Strategy (PDEODE) in the Collection of Third-average Students and Providing them with Mathematical Concepts." Journal of Tikrit university for humanities - مجلة جامعة تكريت للعلوم الانسانية [Online], 27.1 (2020): 344-327. Web. 15 May. 2024