1. European Parliament, Council of the European Union. Regulation (EC) No 549/2004 of the European Parliament and of the Council of 10 March 2004 laying down the framework for the creation of the single European sky (the framework regulation). Strasbourg: European Parliament, Council of the European Union; 2004.
2. Air traffic management—freeing Europe's airspace—white paper;Commission of the European Communities,1996
3. SESAR Joint Undertaking. A proposal for the future architecture of the European airspace. Brussels: SESAR Joint Undertaking; 2019.
4. EUROCONTROL. Daily traffic variation—states [Internet]. Brussels: EUROCONTROL; 2020 [cited 2020 Dec 2]. Available from: https://www.eurocontrol.int/Economics/DailyTrafficVariation-States.html.
5. Council of the European Union. Council regulation (EC) No 219/2007 of 27 February 2007 on the establishment of a Joint Undertaking to develop the new generation European air traffic management system (SESAR). Strasbourg: Council of the European Union; 2007.