Calvo, Natalia, et al. “Borderline Personality Disorder (BPD) Diagnosis With the Self-Report Personality Diagnostic Questionnaire–4+(PDQ-4+): Confirmation of the 3-Factor Structure”. Actas Españolas De Psiquiatría, vol. 40, no. 2, Mar. 2012, pp. 57-62, https://actaspsiquiatria.es/index.php/actas/article/view/674.