http://www.airbus.com/fileadmin/media_gallery/files/press_centre/ACJ_Airbus_Billionaires_study_-_June_2014.pdf
http://www.flyertalk.com/forum/hotel-deals-607/
http://www.flyertalk.com/forum/premium-fare-deals-740/
http://www.wsj.com/articles/4-ways-to-save-big-on-flying-business-class-1426871996
http://www.flyertalk.com/forum/trip-reports-177/