Mitev, Ivan, and Simeon Tsenkulovski. “LOCAL PROCESSING OF NON-METAL MATERIALS WITH CONCENTRATED ENERGY FLOW”. ENVIRONMENT. TECHNOLOGY. RESOURCES. Proceedings of the International Scientific and Practical Conference 3 (January 16, 2024): 183–186. Accessed April 16, 2025. https://journals23.rta.lv/index.php/ETR/article/view/7275.