Güleç, M. Y., Güleç, H., Şimşek, G., Turhan, M., & Sünbül, E. A. (2012). Psychometric properties of the Turkish version of the Patient Health Questionnaire–Somatic, Anxiety, and Depressive Symptoms. Comprehensive Psychiatry, 53(5), 623-629. doi:10.1016/j.comppsych.2011.08.002