1. Amazon Mechanical Turk. (2018). Amazon Mechanical Turk: Human intelligence though an API. Retrieved from
https://www.mturk.com/
2. Centers for Disease Control & Prevention (CDC). (2017a). Quitting smoking. Retrieved from
https://www.cdc.gov/tobacco/data_statistics/fact_sheets/cessation/quitting/index.htm
3. Centers for Disease Control & Prevention (CDC). (2017b). Fast facts. Retrieved from
https://www.cdc.gov/tobacco/data_statistics/fact_sheets/fast_facts/index.htm
4. Centers for Disease Control & Prevention (CDC). (2017c). Obesity and overweight. Retrieved from
https://www.cdc.gov/nchs/fastats/obesity-overweight.htm
5. Charity Miles. (n.d.). Charity miles: Move with purpose. Earn money for charity. Retrieved from
http://www.charitymiles.org/