Chang, Sze-Wei, and Ping-Wen Hwang. “DIFFERENCES AND COMPARISON BETWEEN FAA AND ICAO OBSTACLE RESTRICTION REGULATIONS”. Journal of Air Transport Studies 4, no. 1 (January 1, 2013): 77-88. Accessed August 20, 2022. https://jats.aviationsociety.gr/index.php/JATS/article/view/86.