PREYGER, David, and Vladimir OMELCHENKO. “CASPIAN DILEMMA: HOW TO DELIVER BLUE FUEL TO THE EUROPEAN MARKET”. CENTRAL ASIA AND THE CAUCASUS, vol. 6, no. 3, June 2005, pp. 120-8, http://13.200.237.241/CAC/index.php/cac/article/view/782.