UNICEF (United Nations Children’s Fund). 2007. The state of the world’s children 2008: Child survival. New York: UNICEF.
UNPD (United Nations Population Division). 2007. Urban population (thousands), 1950–2050. In World Population Prospects: The 2006 Revision and World Urbanization Prospects: The 2007 Revision. http://esa.un.org/unup (accessed October 30, 2008).
WCS (Wildlife Conservation Society). 2008. Global Avian Influenza Network for Surveillance (GAINS): Quarter 9—Months 25–27, April 1–June 30, 2008, narrative report. http://www.gains.org/DataTools/GAINSDocs/tabid/114/language/en-US/Default.aspx (accessed October 24, 2008).
WHO (World Health Organization). 2004. Laboratory biosafety manual. 3rd ed. Geneva, Switzerland: WHO.
WHO. 2008a. International health regulations (2005). 2nd ed. Geneva, Switzerland: WHO.
WHO. 2008b. Current WHO phase of pandemic alert. http://www.who.int/csr/disease/avian_influenza/phase/en/index.html (accessed November 11, 2008).
WHO. 2008c. Zoonoses. http://www.who.int/topics/zoonoses/en/ (accessed November 11, 2008).
WIDN (Wildlife Infectious Disease Node). 2008. About the Wildlife Disease Information Node. http://wildlifedisease.nbii.gov/aboutwdin.jsp (accessed on October 31, 2008).
Wolfe, N. D., C. P. Dunavan, and J. Diamond. 2007. Origins of major human infectious diseases. Nature 447(7142):279–283.