Hafezi Birgani, Mehran, and Reza Ghaderi Moghaddam. “Evaluation of Environmental Sustainability Index (ESI) in the Countries Around the Caspian Sea”. Revista Publicando, vol. 5, no. 15(2), June 2018, pp. 788-16, https://revistapublicando.org/revista/index.php/crv/article/view/1399.