Pumar, Begoña, et al. “Longitudinal Study of the Stability of Expresscd Emotion in Families of Schizophrenic Patients: A 9 - Month FolIow-Up”. The Spanish Journal of Psychology, vol. 4, no. 1, Jan. 2001, p. 65, https://revistas.ucm.es/index.php/SJOP/article/view/SJOP0101120065A.