Yook, S., Baek, J. M., & Hahn, S. W. (2017). Psychological Characteristics of Elderly Visited to the Department of Psychiatry : Focused on the Cluster Analysis of The Minnesota Multiphasic Personality Inventory-2. Journal of Korean Geriatric Psychiatry, 21(1), 1–7. https://www.koreamed.org/SearchBasic.php?RID=0112JKGP\%2F2017.21.1.1\&DT=1