1. Soon BT. The global action report on preterm birth Switzerland. The Partnership for Maternal, Newborn & Child Health. Available at: URL: www.who.int/pmnch/media/news/2012/preterm_ birth_report/en/index.html; 2012.
2. Iran (Islamic Republic of) statistics summary (2002- Present). World Health Organization. Available at: URL: http://apps.who.int/gho/data/node.country.countryIRN; 2013.
3. Bradfield L. Core curriculum for neonatal intensive care nursing. Nurse Educ Pract. 2010; 10(6):e59.
4. Chen L, Wang L, Li J, Wang N, Shi Y. Noninvasive ventilation for preterm twin neonates with respiratory distress syndrome: a randomized controlled trial. Sci Rep. 2015; 5:14483.
5. Imani M, Derafshi R, Khalili M, Azizollah A. Comparison of nasal continuous positive airway pressure therapy with and without prophylactic surfactant in preterm neonates. Iran J Neonatol. 2013; 4(3):26-34.
6. Bhatia J. Growth curves: how to best measure growth of the preterm infant. J Pediatr. 2013; 162(3):S2-6.
7. Jones L. Oral feeding readiness in the neonatal intensive care unit. 2012; 3(31):148-55.
8. Velaphi S. Nutritional requirements and parenteral nutrition in preterm infants. South Afr J Clin Nutr. 2011; 24(3):27-31.
9. Chen SS, Tzeng YL, Gau BS, Kuo PC, Chen JY. Effects of prone and supine positioning on gastric residuals in preterm infants: a time series with cross-over study. Int J Nurs Stud. 2013; 50(11):1459-67.
10. Valizadeh S, Hosseini MB, Asghari Jafarabadi M. Comparison of the effect of nutrition in kangaroo mother care and supine positions on gavage residual volume in preterm infants. Evid Based Care J. 2015; 5(1):17-24.
11. Eghbalian F, Moeinipour AR. Effect of neonatal position on oxygen saturation in Hospitalized premature infants with respiratory distress syndrome. Ann Mil Health Sci Res. 2008; 6(1):9-13. 12. Bredemeyer SL, Foster JP. Body positioning for spontaneously breathing preterm infants with apnoea. Cochrane Database Syst Rev. 2012; 6:CD004951.
13. Meneses J, Bhandari V, Alves JG. Nasal intermittent positive-pressure ventilation vs nasal continuous positive airway pressure for preterm infants with respiratory distress syndrome: a systematic review and meta-analysis. Arch Pediatr Adolesc Med. 2012; 166(4):372-6.
14. Zhao J, Gonzalez F, Mu D. Apnea of prematurity: from cause to treatment. Eur J Pediatr. 2011; 170(9):1097-105.
15. Ghorbani F, Asadollahi M, Valizadeh S. Comparison the effect of sleep positioning on cardiorespiratory rate in noninvasive ventilated premature infants. Nurs Midwifery Stud. 2013; 2(2):182-7.
16. Jebreili M, Syeedrasooli A, Headarzadeh M, Gogezadeh M. The effect of body position on gastric residual in preterm infants. Med J Tabriz Univ Med Sci. 2011; 33(2):13-8.