1. Duclos P, Okwo-Bele J, Gacic-Dobo M, Cherian T: Global immunization: status, progress, challenges and future (Opinion). BMC Int Health Hum Rights. 2009, 9 (Suppl 1): S2-10.1186/1472-698X-9-S1-S2.
2. Bofarraj MAM: Knowledge, attitude and practices of mothers regarding immunization of infants and preschool children at Al-Beida City, Libya. Egypt J Pediatr Allergy Immunol. 2011, 9 (1): 29-34.
3. Masud T, Navaratne KV: The Expanded Program on Immunization inPakistan Recommendations for Improving Performance. Health, Nutrition and Population (HNP) Discussion Paper. 2012, Washington, DC: The International Bank for Reconstruction and Development/The World Bank
4. World Health Organization: Media Centre Fact sheets Poliomyelitis. 2013, World Health Organization, [http://www.who.int/mediacentre/factsheets/fs114/en/].
5. World Health Organization: Polio Global Emergency Action Plan 2012-2013. 2012, Pakistan and Afghanistan: Action to Stop Polio Now In Nigeria