Zengrui, Tian, Guillermo Buitrago, and Husam Wahdan. 2018. “Perceived Happiness and Economic Development:Easterlin Paradox and the Latin American Case”. Journal of Research in Business, Economics and Management 10 (2), 1851-59. http://scitecresearch.com/journals/index.php/jrbem/article/view/1378.