1. (ASIS) American Society of Industrial Security. (2010). International, Protection of Assets Manual. http://www.asisonline.org/library/glossary/d.pdf
2. (CRS) Congressional Research Service. (2005). Report for Congress, Terrorism and Security Measures Facing the Water Infrastructure Sector, Jan 2005, p. 4.
3. Hoffman, B. (2006). Inside Terrorism. Columbia University Press, New York, NY, p. 40.
4. (HSC) Homeland Security Council. (2007). National Strategy for Homeland Security. The White House, Washington, DC, Oct 2007, pp. 1–25.
5. Kroll, D. (2010). Securing Our Water Supply: Protecting a Vulnerable Resource, PennWell Publishers, Tulsa, OK, pp. 19–27.