Suharto, U. “ANALYSIS OF THE CONCEPT OF ISLAMIC CHOICE (IKHTIYAR) ON OPPORTUNITY COST AND TIME VALUE OF MONEY IN ISLAMIC ECONOMICS AND FINANCE”. International Journal of Economics, Management and Accounting, vol. 22, no. 2, Dec. 2014, https://journals.iium.edu.my/enmjournal/index.php/enmj/article/view/269.