Dolchinkov, Nikolay, Yanitsa Boyanova, and Nikolay Nichev. “URANIUM MINES IN BULGARIA - ANALYSIS OF THE STATE 30 YEARS AFTER THEIR CLOSURE”. ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference 1 (June 22, 2024): 123–129. Accessed November 23, 2024. https://journals.ru.lv/index.php/ETR/article/view/8002.