Pentz, C. J., D. Rojas, M. B. McCoy, and C. S. Vaughan. “A Case Study in Costa Rica about Personal Happiness: Does Health and Family Communication Have More Influence Than Quantity of Money and Material Goods?”. UNED Research Journal, vol. 5, no. 1, May 2013, pp. 163-70, doi:10.22458/urj.v5i1.214.