Block, Jack (2008). The Q-Sort in character appraisal: Encoding subjective impressions of persons quantitatively. American Psychological Association
Block 1961/1978: The Q-Sort Method in Personality Assessment and Psychiatric Research
Block, Jack (1961/1978): The Q-sort method in personality assessment and psychiatric research. Springfield, IL: Charles C. Thomas. (reprinted in 1978 by Consulting Psychologists Press, Palo Alto, CA)