1. United Nations Children's Emergency Fund.: ‘Every child's birth right: inequities and trends in birth registration’ 2013. Available from:http://www.unicef.org/publications/index_71514.html
2. United Nations Children's Emergency Fund.: ‘Expanding immunization coverage’ 2011. Available from:http://www.unicef.org/immunization/index_coverage.html
3. Bill & Melinda Gates Foundation.: ‘Create low-cost cell phone‐based solutions for improved uptake and coverage of childhood vaccinations’ 2011. Available from:http://www.grandchallenges.org/MeasureHealthStatus/Topics/CellPhoneApps/Pages/Round7.aspx
4. Longitudinal Study of Automatic Face Recognition