Human Security Report 2009/2010. Human Security Report Project. http://www.hsrgroup.org/human-security-reports/20092010/overview.aspxArchivado el 29 de julio de 2012 en Wayback Machine. (Retrieved 14 February 2012.) For longer-term trends, see Steven Pinker, The Better Angels of Our Nature: Why Violence has Declined (New York: Viking, 2011) and literature cited therein.
Human Security Report 2009/2010. Human Security Report Project. http://www.hsrgroup.org/human-security-reports/20092010/overview.aspxArchivado el 29 de julio de 2012 en Wayback Machine. (Retrieved 14 February 2012.) For longer-term trends, see Steven Pinker, The Better Angels of Our Nature: Why Violence has Declined (New York: Viking, 2011) and literature cited therein.