Крижанівський, Є. І. (2015). Scientific and Organizational Principles of Increasing of Extraction of Domestic Oil and Gas and Diversification of Energy Resources Supply for Improving Energy Security of Ukraine. Scientific Bulletin of Ivano-Frankivsk National Technical University of Oil and Gas (Series: Economics and Management in the Oil and Gas Industry), 2(12), 7–14. Retrieved from https://eung.nung.edu.ua/index.php/ecom/article/view/109