De Avila Arroyo, J. P., Yago, M., Nasir, M. A., & Wu, J. (2014). Strategic Alliance in Energy Sector & Implications for Economic Growth and Technical Efficiency: The Case of Petrobras and Galp. International Journal of Energy Economics and Policy, 4(4), 759–771. Retrieved from https://econjournals.com.tr/index.php/ijeep/article/view/953