Bahmanshir, Reza Darisavi, et al. “Reversibility Test of Oil Demand Function of OECD Countries Importing Oil from Iran With an Emphasis on Technological and Environmental Considerations: Symmetric and Asymmetric Models”. International Journal of Energy Economics and Policy, vol. 8, no. 2, Mar. 2018, pp. 132-9, https://econjournals.net.tr/index.php/ijeep/article/view/6116.