1. See supporting material on Science Online.
2. World Medical Association “Policy: Declaration of Washington on Biological Weapons” (Document 17.400 World Medical Association Ferney-Voltaire France 2002); available at www.wma.net/e/policy/b1.htm.
3. Biotechnology Weapons and Humanity (Harwood Academic Publishers London 1999)British Medical Association .
4. Committee on Research Standards and Practice to Prevent the Destructive Application of Biotechnology, National Research Council, Biotechnology Research in an Age of Terrorism (National Academies Press, Washington, DC, 2004).
5. House of Commons “Security of Research” (Select Committee on Science and Technology Eighth Report 2003); available at www.publications.parliament.uk/pa/cm200203/cmselect/cmsctech/415/41515.htm.