Molero, Fernando, Isabel Cuadrado, Marisol Navas, and J. Francisco Morales. “Relations and Effects of Transformational Leadership: A Comparative Analysis with Traditional Leadership Styles”. The Spanish Journal of Psychology, vol. 10, vol. 10, no. 2, 2007, pp. 358-6, https://revistas.ucm.es/index.php/SJOP/article/view/SJOP0707220358A.