Ranjbar, Samira, and Ali Esmailzadeh Maghari. “The Feasibility of Productivity Improvement Using the Approach of Virtual Economy”. International Journal of Economics and Financial Issues 7, no. 3 (June 29, 2017): 371–376. Accessed November 24, 2024. https://mail.econjournals.com/index.php/ijefi/article/view/4806.