1. 2013 International Bedroom Poll: Summary of Findings
https://www.sleepfoundation.org/professionals/sleep-americar-polls/2013-international-bedroom-poll
2. 2005 Sleep in America Poll
https://www.sleepfoundation.org/professionals/sleep-america-polls
3. 2002 Sleep in America Poll
https://www.sleepfoundation.org/professionals/sleep-americar-polls/2002-adult-sleep-habits
4. Obesity and Overweight
https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight