Bosak, P., A. Lutsyk, and K. Korol. “ENVIRONMENTAL CHARACTERISTICS OF THE SLAVKA AND THE OPIR RIVERS ON THE TERITORY OF SLAVSK ( LVIV REGION)”. Bulletin of Lviv State University of Life Safety 20 (December 27, 2019): 80-84. Accessed July 3, 2024. https://journal.ldubgd.edu.ua/index.php/Visnuk/article/view/1593.