Taherifard, Ali, Fazel Moridi Farimani, and Zarir Negin-Taji. “The Efficiency of Upstream Petroleum Contracts: Risk Service Contract in Focus”. International Journal of Energy Economics and Policy 15, no. 4 (June 25, 2025): 367–377. Accessed February 9, 2026. https://www.econjournals.com/index.php/ijeep/article/view/18363.