^Douglas, John E.; Burgess, Ann W.; Burgess, Allen G.; Ressler, Robert K. (1997) [1992]. Crime Classification Manual: A Standard System for Investigating and Classifying Violent Crimes. Jossey-Bass.
ISBN0-7879-3885-8.
^George B. Palermo; Richard N. Kocsis (2005). Offender Profiling: An Introduction To The Sociopsychological Analysis Of Violent Crime. American Series in Behavioral Science and Law. Charles C Thomas Publisher. pp. 145–146.
ISBN0-398-07549-2.
^Douglas, John E.; Burgess, Ann W.; Burgess, Allen G.; Ressler, Robert K. (2006). Crime classification manual : a standard system for investigating and classifying violent crime (2nd ed.). San Francisco, Calif.: Jossey-Bass.
ISBN0-7879-8501-5.