1. Diener E, Inglehart R, Tay L. Theory and validity of life satisfaction scales. Social Indicators Research. 2013;112(3):497-527. DOI: 10.1007/s11205‐012‐0076‐y
2. United Nations Development Program. Human development report. New York: Oxford University Press; 2008.
3. The World Bank Group. World development indicators. The World Bank; 2009.
4. Brooks AC. Gross national happiness: Why happiness matters for America and what we can do to get more of it. New York: Basic Books; 2008.
5. Gill TM. Quality of life assessment: Values and pitfalls. Journal of the Royal Society of Medicine. 1995;88(12):680-682.