1. Cases of wild poliovirus by country and year
2. Tracking progress toward global polio eradication–worldwide, 2009–2010;MMWR Morb Mortal Wkly Rep,2011
3. Poliomyelitis: intensification of the global eradication initiative
4. Outbreaks of paralytic poliomyelitis, 1976–1995;Patriarca;J Infect Dis,1997
5. Indices & data. In: Human development report 2013. Sustainability and equity: a better future for all;Human Development Report 2011 Team,2013