Redif, Moustafa, and Mourad Smaail. “The Economic Importance of the Services Sector Iinternational and Local Level ”. Milev Journal of Research and Studies 4, no. 1 (June 30, 2018): 475–494. Accessed November 22, 2024. https://jiamcs.centre-univ-mila.dz/index.php/mjrs/article/view/1294.