Tarek, Bel Hadj. “Product Differentiation and Intra-Industrial Trade: Quantitative Assessment in the Case of Tunisia”. Journal of Economics and Behavioral Studies 4, no. 10 (October 15, 2012): pp. 570-587. Accessed July 3, 2024. https://ojs.amhinternational.com/index.php/jebs/article/view/358.