Abdullah Al-Ajeeli, A.H. 2021. (The Effect of the Crashing Waves Strategy on Developing Productive Thinking of Second-grade Students in the Middle School in Social Sciences). Journal of Tikrit University for Humanities. 28, 12, 2 (Dec. 2021), 486–505. DOI:https://doi.org/10.25130/jtuh.28.12.2.2021.23.