Herrera Sánchez, Isabel María, José María León Rubio, and Silvia Medina Anzano. “A Pragmatic Guideline for Evaluation of Social Intervention”. The Spanish Journal of Psychology, vol. 8, vol. 8, no. 1, 2005, pp. 21-29, https://revistas.ucm.es/index.php/SJOP/article/view/SJOP0505120021A.