Chynchenko, Yuriy, and Volodymyr Kharchenko. “THE FREE ROUTE AIRSPACE UKRAINE IMPLEMENTATION CORNERSTONES”. Proceedings of National Aviation University 86, no. 1 (April 15, 2021): 6–12. Accessed April 19, 2024. https://jrnl.nau.edu.ua/index.php/visnik/article/view/15438.