Krastev, Krastyu. “THE CONTRIBUTION OF THE MILITARY SCHOOL TO THE BUILDING OF THE NATIONAL SECURITY SYSTEM OF BULGARIA IN THE PERIOD 1878-1885”. ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference 4 (June 22, 2024): 155–159. Accessed November 22, 2024. https://journals23.rta.lv/index.php/ETR/article/view/8231.