“DEVELOPMENT AND APPLICATION OF VIRTUAL HIERARCHICAL STRUCTURES OF OES UKRAINE FOR MODES SIMULATION AND STAFF TRAINING”. Visnyk of Vinnytsia Politechnical Institute, no. 1 (March 16, 2016): 101–107. Accessed October 10, 2026. https://visnyk.vntu.edu.ua/index.php/visnyk/article/view/1884.