1. Expanded programme on immunization;K Keja;World health statistics report,1988
2. Beyond expectations: 40 years of EPI;M Chan;The Lancet
3. Global immunization: status, progress, challenges and future;P Duclos;BMC international health and human rights,2009
4. Using immunization delivery strategies to accelerate progress in Africa towards achieving the Millennium Development Goals;CJ Clements;Vaccine,2008
5. Routine immunization in the WHO African Region: Progress, challenges and way forward;R Mihigo;African Health Monitor