AMOUMEN, R., and A. AOUN. “The Effectiveness of Using Cooperative Learning in the Mastery of the Fourth Year Primary Students of the Four Arithmetic Skills in a Sample of Educational Institutions in the City of Ouargla”. Social Sciences Journal, Vol. 4, no. 2, 1, pp. 01-21, http://journals.lagh-univ.dz/index.php/ssj/article/view/3288.