1. World Bank. 2012 World Bank Classification According To GNI. Available from: http://data.worldbank.org/country.
2. Population, Education and Development. Department of Economic and Social Affairs, Population Division New York: United Nations; 2003;.
3. Global cancer statistics
4. Ferlay J, Shin HR, Bray F, Forman D, Mathers C, Parkin DM. Cancer Incidence and Mortality Worldwide: IARC. GLOBOCAN 2008 v1.2, Cancer Incidence and Mortality Worldwide: IARC CancerBase No. 10 [Internet]. Lyon, France: International Agency for Research on Cancer; 2010. Available from: http://globocan.iarc.fr.
5. Curado MP, Edwards B, Shin HR, Storm H, Ferlay J, Heanue M, Boyle P. Cancer Incidence in Five Continents. Vol. IX Lyon: IARC Scientific Publications; 2007;.