1. PMNCH . Born too soon: the global action report on preterm birth. who. World Health organization. Available: http://www.who.int/pmnch/knowledge/publications/preterm_birth_report/en/
2. UNICEF DATA . Neonatal mortality. Available: https://data.unicef.org/topic/child-survival/neonatal-mortality/
3. WHO . Neonatal mortality. who. World Health organization. Available: http://www.who.int/gho/child_health/mortality/neonatal_text/en/
4. WHO . The worldwide incidence of preterm birth: a systematic review of maternal mortality and morbidity. who. World Health organization. Available: https://www.who.int/bulletin/volumes/88/1/08-062554/en/
5. Global report on preterm birth and stillbirth (1 of 7): definitions, description of the burden and opportunities to improve data;Lawn;BMC Pregnancy Childbirth,2010