
https://www.crisisgroup.org/europe-central-asia/western-europemediterranean/turkiye/promising-route-peace-turkiyes-pkk-conflict

http://www.aviationlaw.eu/wp/wp-content/uploads/2013/09/Freedoms-of-the-Air-Explained.pdf

https://www.crisisgroup.org/europe-central-asia/war-peace-season-4