Croddy, Eric and Wirtz, James J. Weapons of Mass Destruction: An Encyclopedia of Worldwide Policy, Technology, and History, (Google Books), ABC-CLIO, Santa Barbara, California: 2005, p. 11, (ISBN1851094903).
Avery, Donald. The Science of War, (Google Books), University of Toronto Press, Toronto: 1998, p. 165, (ISBN0802059961).
Wright, Susan. Biological Warfare and Disarmament, (Google Books), Rowman & Littlefield, 2002, p. 138, (ISBN0742524698).
