MATVIYENKO V, YEROMENKO V. THE GAS TRANSPORTATION SYSTEM OF UKRAINE IN CONDITIONS OF EXTERNAL THREAT TO ENERGY SECURITY STATE . ESG [Internet]. 2014 Jun. 30 [cited 2026 Jul. 15];69:159-64. Available from: https://www.bulletin-esgeograph.org.ua/esg/article/view/69-matviyenko-et-al-159-164