"ICAO Circular 259-AN/153"(PDF). Aircraft Accident Digest (34). International Civil Aviation Organization: 97–118. 1987. Archived from the original(PDF) on 4 May 2018. Retrieved 24 September 2019.
"ICAO Circular 259-AN/153"(PDF). Aircraft Accident Digest (34). International Civil Aviation Organization: 97–118. 1987. Archived from the original(PDF) on 4 May 2018. Retrieved 24 September 2019.