Bijan Vasigh, Tom Tacker, Ken Fleming. Introduction to Air Transport Economics: From Theory to Applications.
Ashgate Publishing, Ltd., 2008. ISBN0-7546-7081-3. On Google Books. Page 156
“Taking the sixth” (英語). Flightglobal.com (2006年2月20日). 2018年12月10日閲覧。
icao.int
icao.int
International Air Services Transit Agreement - list of signatory states. The document is not dated, but includes Kazakhstan, which notified the U.S. Secretary of State of its acceptance of the treaty in July 2007.