1. Wake Vortex Research—A Retrospective Look
2. Eurocontrol, "Challenges of Growth 2013," Summary Report, http://www.eurocontrol.int/statfor, 2013.
3. SAFO 12007, 2012, Safety Alert for Operators, Federal Aviation Administration, http://www.faa.gov/other_visit/aviation_industry/airline_operators/airline_safety/safo/all_safos/media/2012/SAFO12007.pdf [cited 21 October 2013].