1. ACSI. (2014). Benchmarks by industry: Airlines. Retrieved March 4, 2014, from http://www.theacsi.org/?option=com_content&view=article&id=147&catid=14&Itemid=212&i=Airlines
2. Anthony, S. D. (2008, April 3). A playbook for moving down market. Bloomberg Businessweek. Retrieved from http://www.businessweek.com/stories/2008-04-03/a-playbook-for-moving-down-marketbusinessweek-business-news-stock-market-and-financial-advice
3. Facing low-cost competitors: Lessons from U.S. airlines;Barkin;McKinsey Quarterly,1995
4. Applying yield management pricing to your service business;Berman;Business Horizons,2005
5. Competing in tough times;Berman,2011