1. Global immunization: status, progress, challenges, and future;Duclos;BMC Int Health Human Rights,2009
2. WHO and UNICEF. Immunisation summary: a statistical reference containing data through 2011. New York, USA: UNICEF Statistics and Monitoring Section Division of Policy and Practice; 2013. https://www.unicef.org/Immunisation/files/EN-ImmSumm-2013.pdf.
3. State of equity: childhood immunization in the World Health Organization African Region;Casey;The Pan African Med J,2017
4. Expanded programme on immunization (EPI) regional fact sheet 2017;Asia;World Heal Organ,2017
5. Child health and immunisation: a macro-perspective;Das;Econ Political Weekly,2000