AU - Saidia, Houari AU - Messaoudi, Khaled AU - Beneddine, Kamel OP - pp. 49-63 T1 - The impact of physical sports activities in the collective development of some mental skills among middle school students (13-15 years) [Article] UL - http://search.shamaa.org/PDF/Articles/AEIr/IrNo22Y2017/ir_2017-n22_049-063_eng.pdf Full text (PDF) 1 http://search.shamaa.org/fulltext.gif