SALAH OMER AL-HEAYLI, B. and Khaled Khear Alden AL-Hamdani Abstract, D. (2018) “Concentration of Attention and their Relationship with personal types (A, B) for preparatory school students”, College of Basic Education Research Journal, 14(2), pp. 99–138. doi: 10.33899/berj.2018.146284.