Montoya, Pedro, J. Javier Campos, and Rainer Schandry. “See red? Turn pale? Unveiling Emotions through Cardiovascular and Hemodynamic Changes”. The Spanish Journal of Psychology, vol. 8, vol. 8, no. 1, 2005, pp. 79-85, https://revistas.ucm.es/index.php/SJOP/article/view/SJOP0505120079A.