Dávila de León, María Celeste, y Fernando Chacón Fuertes. «Prediction of Longevity of Volunteer Service: A Basic Alternative Proposal». The Spanish Journal of Psychology 10, no. 1 (mayo 11, 2007): 115–121. Accedido julio 22, 2026. https://revistas.ucm.es/index.php/SJOP/article/view/SJOP0707120115A.