1. Engle WA. Age terminology during the perinatal period. Pediatrics. 2004;114:1362–4.
2. The Committee on Fetus and Newborn. American academy of pediatrics policy statement. Age terminology during the perinatal period. Pediatrics. 2004;114:1362–4.
3. Whisett JA, Rice WR, Warner BB, et al. Chapter 26. Acute respiratory disorders. In: MacDonald MG, Mullett MM, Seshia MMK, editors. Avery’s neonatology. 7th ed. Philadelphia: Lippincott Williams & Wilkins; 2016. p. 397–415.
4. Ardell S, Pfister RH, Soll R. Animal derived surfactant compared to protein-free synthetic surfactant preparations in preterm infants that have or are at high risk for respiratory distress syndrome. 24 Aug 2015. Cochrane Library 2015.
5. Whitelaw A, Osredkar D, Thoresen M. Neurological and neuromuscular disorders. Chapter 46. In: MacDonald MG, Mullett MM, Seshia MMK, editors. Avery’s neonatology. 7th ed. Philadelphia: Lippincott Williams & Wilkins; 2016. p. 994–1016.